diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d89b85527..41dbd4243 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,6 +8,10 @@ jobs:
       PGHOST: localhost
       PGUSER: dummy
       RAILS_ENV: test
+      BUNDLE_JOBS: 4
+      BUNDLE_RETRY: 3
+      BUNDLE_PATH: vendor/bundle
+      DISABLE_SPRING: 1
     services:
       postgres:
         image: postgres:10.8
@@ -31,13 +35,15 @@ jobs:
         uses: actions/cache@v1
         with:
           path: vendor/bundle
-          key: v1-${{ runner.os }}-gems-${{ hashFiles('**/good_job.gemspec') }}-${{ hashFiles('**/Gemfile') }}
+          key: v1-${{ runner.os }}-gems-${{ hashFiles('**/good_job.gemspec') }}-${{ hashFiles('**/Gemfile.lock') }}-${{ hashFiles('**/Appraisals') }}
           restore-keys: |
             v1-${{ runner.os }}-gems-
-      - name: Install gems
-        run: |
-          bundle config path vendor/bundle
-          bundle install --jobs 4 --retry 3 && bundle clean
+      - name: Install bundler
+        run: gem update --system && gem install bundler -v $(grep -A 1 "BUNDLED WITH" Gemfile.lock | tail -1 | tr -d " ")
+      - name: Install Gemfile gems
+        run: bundle install && bundle clean
+      - name: Install Appraisal gems
+        run: bundle exec appraisal install
       # /Dependencies
 
       - name: Setup test database
@@ -45,4 +51,4 @@ jobs:
           cd spec/dummy
           bin/rails db:test:prepare
       - name: Run tests
-        run: RAILS_ENV=test DISABLE_SPRING=1 bin/rspec
+        run: bundle exec appraisal bin/rspec
diff --git a/.gitignore b/.gitignore
index b84e0aec7..eeadbf380 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,4 +4,3 @@ pkg/
 spec/dummy/log/*.log
 spec/dummy/storage/
 spec/dummy/tmp/
-Gemfile.lock
diff --git a/Appraisals b/Appraisals
new file mode 100644
index 000000000..89275845b
--- /dev/null
+++ b/Appraisals
@@ -0,0 +1,11 @@
+appraise "rails-5.1" do
+  gem "rails", "~> 5.1.0"
+end
+
+appraise "rails-5.2" do
+  gem "rails", "~> 5.2.0"
+end
+
+appraise "rails-6.0" do
+  gem "rails", "~> 6.0.0"
+end
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 000000000..5b72bcc56
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,199 @@
+PATH
+  remote: .
+  specs:
+    good_job (0.2.0)
+      concurrent-ruby (>= 1.0.2)
+      rails (>= 5.1.0)
+      thor (>= 0.14.1)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    actioncable (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      nio4r (~> 2.0)
+      websocket-driver (>= 0.6.1)
+    actionmailbox (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activejob (= 6.0.2.1)
+      activerecord (= 6.0.2.1)
+      activestorage (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      mail (>= 2.7.1)
+    actionmailer (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      actionview (= 6.0.2.1)
+      activejob (= 6.0.2.1)
+      mail (~> 2.5, >= 2.5.4)
+      rails-dom-testing (~> 2.0)
+    actionpack (6.0.2.1)
+      actionview (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      rack (~> 2.0, >= 2.0.8)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.2.0)
+    actiontext (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activerecord (= 6.0.2.1)
+      activestorage (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      nokogiri (>= 1.8.5)
+    actionview (6.0.2.1)
+      activesupport (= 6.0.2.1)
+      builder (~> 3.1)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.1, >= 1.2.0)
+    activejob (6.0.2.1)
+      activesupport (= 6.0.2.1)
+      globalid (>= 0.3.6)
+    activemodel (6.0.2.1)
+      activesupport (= 6.0.2.1)
+    activerecord (6.0.2.1)
+      activemodel (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+    activestorage (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activejob (= 6.0.2.1)
+      activerecord (= 6.0.2.1)
+      marcel (~> 0.3.1)
+    activesupport (6.0.2.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+      zeitwerk (~> 2.2)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
+    appraisal (2.2.0)
+      bundler
+      rake
+      thor (>= 0.14.0)
+    builder (3.2.4)
+    concurrent-ruby (1.1.6)
+    crass (1.0.6)
+    database_cleaner (1.8.3)
+    diff-lcs (1.3)
+    erubi (1.9.0)
+    faraday (0.17.3)
+      multipart-post (>= 1.2, < 3)
+    faraday-http-cache (2.0.0)
+      faraday (~> 0.8)
+    gem-release (2.1.1)
+    github_changelog_generator (1.15.0)
+      activesupport
+      faraday-http-cache
+      multi_json
+      octokit (~> 4.6)
+      rainbow (>= 2.2.1)
+      rake (>= 10.0)
+      retriable (~> 3.0)
+    globalid (0.4.2)
+      activesupport (>= 4.2.0)
+    i18n (1.8.2)
+      concurrent-ruby (~> 1.0)
+    loofah (2.4.0)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.5.9)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    marcel (0.3.3)
+      mimemagic (~> 0.3.2)
+    method_source (0.9.2)
+    mimemagic (0.3.4)
+    mini_mime (1.0.2)
+    mini_portile2 (2.4.0)
+    minitest (5.14.0)
+    multi_json (1.14.1)
+    multipart-post (2.1.1)
+    nio4r (2.5.2)
+    nokogiri (1.10.7)
+      mini_portile2 (~> 2.4.0)
+    octokit (4.16.0)
+      faraday (>= 0.9)
+      sawyer (~> 0.8.0, >= 0.5.3)
+    pg (0.21.0)
+    public_suffix (4.0.3)
+    rack (2.1.2)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails (6.0.2.1)
+      actioncable (= 6.0.2.1)
+      actionmailbox (= 6.0.2.1)
+      actionmailer (= 6.0.2.1)
+      actionpack (= 6.0.2.1)
+      actiontext (= 6.0.2.1)
+      actionview (= 6.0.2.1)
+      activejob (= 6.0.2.1)
+      activemodel (= 6.0.2.1)
+      activerecord (= 6.0.2.1)
+      activestorage (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      bundler (>= 1.3.0)
+      railties (= 6.0.2.1)
+      sprockets-rails (>= 2.0.0)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
+    railties (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      method_source
+      rake (>= 0.8.7)
+      thor (>= 0.20.3, < 2.0)
+    rainbow (3.0.0)
+    rake (13.0.1)
+    retriable (3.1.2)
+    rspec-core (3.9.1)
+      rspec-support (~> 3.9.1)
+    rspec-expectations (3.9.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-mocks (3.9.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-rails (3.9.0)
+      actionpack (>= 3.0)
+      activesupport (>= 3.0)
+      railties (>= 3.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.2)
+    sawyer (0.8.2)
+      addressable (>= 2.3.5)
+      faraday (> 0.8, < 2.0)
+    sprockets (4.0.0)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
+    sprockets-rails (3.2.1)
+      actionpack (>= 4.0)
+      activesupport (>= 4.0)
+      sprockets (>= 3.0.0)
+    thor (1.0.1)
+    thread_safe (0.3.6)
+    tzinfo (1.2.6)
+      thread_safe (~> 0.1)
+    websocket-driver (0.7.1)
+      websocket-extensions (>= 0.1.0)
+    websocket-extensions (0.1.4)
+    zeitwerk (2.2.2)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  appraisal
+  database_cleaner
+  gem-release
+  github_changelog_generator
+  good_job!
+  pg
+  rspec-rails
+
+BUNDLED WITH
+   2.1.2
diff --git a/gemfiles/rails_5.1.gemfile b/gemfiles/rails_5.1.gemfile
new file mode 100644
index 000000000..6100e830b
--- /dev/null
+++ b/gemfiles/rails_5.1.gemfile
@@ -0,0 +1,7 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "rails", "~> 5.1.0"
+
+gemspec path: "../"
diff --git a/gemfiles/rails_5.1.gemfile.lock b/gemfiles/rails_5.1.gemfile.lock
new file mode 100644
index 000000000..046868700
--- /dev/null
+++ b/gemfiles/rails_5.1.gemfile.lock
@@ -0,0 +1,176 @@
+PATH
+  remote: ..
+  specs:
+    good_job (0.2.0)
+      concurrent-ruby (>= 1.0.2)
+      rails (>= 5.1.0)
+      thor (>= 0.14.1)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    actioncable (5.1.7)
+      actionpack (= 5.1.7)
+      nio4r (~> 2.0)
+      websocket-driver (~> 0.6.1)
+    actionmailer (5.1.7)
+      actionpack (= 5.1.7)
+      actionview (= 5.1.7)
+      activejob (= 5.1.7)
+      mail (~> 2.5, >= 2.5.4)
+      rails-dom-testing (~> 2.0)
+    actionpack (5.1.7)
+      actionview (= 5.1.7)
+      activesupport (= 5.1.7)
+      rack (~> 2.0)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    actionview (5.1.7)
+      activesupport (= 5.1.7)
+      builder (~> 3.1)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.3)
+    activejob (5.1.7)
+      activesupport (= 5.1.7)
+      globalid (>= 0.3.6)
+    activemodel (5.1.7)
+      activesupport (= 5.1.7)
+    activerecord (5.1.7)
+      activemodel (= 5.1.7)
+      activesupport (= 5.1.7)
+      arel (~> 8.0)
+    activesupport (5.1.7)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
+    appraisal (2.2.0)
+      bundler
+      rake
+      thor (>= 0.14.0)
+    arel (8.0.0)
+    builder (3.2.4)
+    concurrent-ruby (1.1.6)
+    crass (1.0.6)
+    database_cleaner (1.8.3)
+    diff-lcs (1.3)
+    erubi (1.9.0)
+    faraday (0.17.3)
+      multipart-post (>= 1.2, < 3)
+    faraday-http-cache (2.0.0)
+      faraday (~> 0.8)
+    gem-release (2.1.1)
+    github_changelog_generator (1.15.0)
+      activesupport
+      faraday-http-cache
+      multi_json
+      octokit (~> 4.6)
+      rainbow (>= 2.2.1)
+      rake (>= 10.0)
+      retriable (~> 3.0)
+    globalid (0.4.2)
+      activesupport (>= 4.2.0)
+    i18n (1.8.2)
+      concurrent-ruby (~> 1.0)
+    loofah (2.4.0)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.5.9)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    method_source (0.9.2)
+    mini_mime (1.0.2)
+    mini_portile2 (2.4.0)
+    minitest (5.14.0)
+    multi_json (1.14.1)
+    multipart-post (2.1.1)
+    nio4r (2.5.2)
+    nokogiri (1.10.9)
+      mini_portile2 (~> 2.4.0)
+    octokit (4.16.0)
+      faraday (>= 0.9)
+      sawyer (~> 0.8.0, >= 0.5.3)
+    pg (1.2.2)
+    public_suffix (4.0.3)
+    rack (2.2.2)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails (5.1.7)
+      actioncable (= 5.1.7)
+      actionmailer (= 5.1.7)
+      actionpack (= 5.1.7)
+      actionview (= 5.1.7)
+      activejob (= 5.1.7)
+      activemodel (= 5.1.7)
+      activerecord (= 5.1.7)
+      activesupport (= 5.1.7)
+      bundler (>= 1.3.0)
+      railties (= 5.1.7)
+      sprockets-rails (>= 2.0.0)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
+    railties (5.1.7)
+      actionpack (= 5.1.7)
+      activesupport (= 5.1.7)
+      method_source
+      rake (>= 0.8.7)
+      thor (>= 0.18.1, < 2.0)
+    rainbow (3.0.0)
+    rake (13.0.1)
+    retriable (3.1.2)
+    rspec-core (3.9.1)
+      rspec-support (~> 3.9.1)
+    rspec-expectations (3.9.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-mocks (3.9.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-rails (3.9.0)
+      actionpack (>= 3.0)
+      activesupport (>= 3.0)
+      railties (>= 3.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.2)
+    sawyer (0.8.2)
+      addressable (>= 2.3.5)
+      faraday (> 0.8, < 2.0)
+    sprockets (4.0.0)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
+    sprockets-rails (3.2.1)
+      actionpack (>= 4.0)
+      activesupport (>= 4.0)
+      sprockets (>= 3.0.0)
+    thor (1.0.1)
+    thread_safe (0.3.6)
+    tzinfo (1.2.6)
+      thread_safe (~> 0.1)
+    websocket-driver (0.6.5)
+      websocket-extensions (>= 0.1.0)
+    websocket-extensions (0.1.4)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  appraisal
+  database_cleaner
+  gem-release
+  github_changelog_generator
+  good_job!
+  pg
+  rails (~> 5.1.0)
+  rspec-rails
+
+BUNDLED WITH
+   2.1.2
diff --git a/gemfiles/rails_5.2.gemfile b/gemfiles/rails_5.2.gemfile
new file mode 100644
index 000000000..5a706dcb6
--- /dev/null
+++ b/gemfiles/rails_5.2.gemfile
@@ -0,0 +1,7 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "rails", "~> 5.2.0"
+
+gemspec path: "../"
diff --git a/gemfiles/rails_5.2.gemfile.lock b/gemfiles/rails_5.2.gemfile.lock
new file mode 100644
index 000000000..3a9ff18b5
--- /dev/null
+++ b/gemfiles/rails_5.2.gemfile.lock
@@ -0,0 +1,184 @@
+PATH
+  remote: ..
+  specs:
+    good_job (0.2.0)
+      concurrent-ruby (>= 1.0.2)
+      rails (>= 5.1.0)
+      thor (>= 0.14.1)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    actioncable (5.2.4.1)
+      actionpack (= 5.2.4.1)
+      nio4r (~> 2.0)
+      websocket-driver (>= 0.6.1)
+    actionmailer (5.2.4.1)
+      actionpack (= 5.2.4.1)
+      actionview (= 5.2.4.1)
+      activejob (= 5.2.4.1)
+      mail (~> 2.5, >= 2.5.4)
+      rails-dom-testing (~> 2.0)
+    actionpack (5.2.4.1)
+      actionview (= 5.2.4.1)
+      activesupport (= 5.2.4.1)
+      rack (~> 2.0, >= 2.0.8)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    actionview (5.2.4.1)
+      activesupport (= 5.2.4.1)
+      builder (~> 3.1)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.3)
+    activejob (5.2.4.1)
+      activesupport (= 5.2.4.1)
+      globalid (>= 0.3.6)
+    activemodel (5.2.4.1)
+      activesupport (= 5.2.4.1)
+    activerecord (5.2.4.1)
+      activemodel (= 5.2.4.1)
+      activesupport (= 5.2.4.1)
+      arel (>= 9.0)
+    activestorage (5.2.4.1)
+      actionpack (= 5.2.4.1)
+      activerecord (= 5.2.4.1)
+      marcel (~> 0.3.1)
+    activesupport (5.2.4.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
+    appraisal (2.2.0)
+      bundler
+      rake
+      thor (>= 0.14.0)
+    arel (9.0.0)
+    builder (3.2.4)
+    concurrent-ruby (1.1.6)
+    crass (1.0.6)
+    database_cleaner (1.8.3)
+    diff-lcs (1.3)
+    erubi (1.9.0)
+    faraday (0.17.3)
+      multipart-post (>= 1.2, < 3)
+    faraday-http-cache (2.0.0)
+      faraday (~> 0.8)
+    gem-release (2.1.1)
+    github_changelog_generator (1.15.0)
+      activesupport
+      faraday-http-cache
+      multi_json
+      octokit (~> 4.6)
+      rainbow (>= 2.2.1)
+      rake (>= 10.0)
+      retriable (~> 3.0)
+    globalid (0.4.2)
+      activesupport (>= 4.2.0)
+    i18n (1.8.2)
+      concurrent-ruby (~> 1.0)
+    loofah (2.4.0)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.5.9)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    marcel (0.3.3)
+      mimemagic (~> 0.3.2)
+    method_source (0.9.2)
+    mimemagic (0.3.4)
+    mini_mime (1.0.2)
+    mini_portile2 (2.4.0)
+    minitest (5.14.0)
+    multi_json (1.14.1)
+    multipart-post (2.1.1)
+    nio4r (2.5.2)
+    nokogiri (1.10.9)
+      mini_portile2 (~> 2.4.0)
+    octokit (4.16.0)
+      faraday (>= 0.9)
+      sawyer (~> 0.8.0, >= 0.5.3)
+    pg (1.2.2)
+    public_suffix (4.0.3)
+    rack (2.2.2)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails (5.2.4.1)
+      actioncable (= 5.2.4.1)
+      actionmailer (= 5.2.4.1)
+      actionpack (= 5.2.4.1)
+      actionview (= 5.2.4.1)
+      activejob (= 5.2.4.1)
+      activemodel (= 5.2.4.1)
+      activerecord (= 5.2.4.1)
+      activestorage (= 5.2.4.1)
+      activesupport (= 5.2.4.1)
+      bundler (>= 1.3.0)
+      railties (= 5.2.4.1)
+      sprockets-rails (>= 2.0.0)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
+    railties (5.2.4.1)
+      actionpack (= 5.2.4.1)
+      activesupport (= 5.2.4.1)
+      method_source
+      rake (>= 0.8.7)
+      thor (>= 0.19.0, < 2.0)
+    rainbow (3.0.0)
+    rake (13.0.1)
+    retriable (3.1.2)
+    rspec-core (3.9.1)
+      rspec-support (~> 3.9.1)
+    rspec-expectations (3.9.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-mocks (3.9.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-rails (3.9.0)
+      actionpack (>= 3.0)
+      activesupport (>= 3.0)
+      railties (>= 3.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.2)
+    sawyer (0.8.2)
+      addressable (>= 2.3.5)
+      faraday (> 0.8, < 2.0)
+    sprockets (4.0.0)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
+    sprockets-rails (3.2.1)
+      actionpack (>= 4.0)
+      activesupport (>= 4.0)
+      sprockets (>= 3.0.0)
+    thor (1.0.1)
+    thread_safe (0.3.6)
+    tzinfo (1.2.6)
+      thread_safe (~> 0.1)
+    websocket-driver (0.7.1)
+      websocket-extensions (>= 0.1.0)
+    websocket-extensions (0.1.4)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  appraisal
+  database_cleaner
+  gem-release
+  github_changelog_generator
+  good_job!
+  pg
+  rails (~> 5.2.0)
+  rspec-rails
+
+BUNDLED WITH
+   2.1.2
diff --git a/gemfiles/rails_6.0.gemfile b/gemfiles/rails_6.0.gemfile
new file mode 100644
index 000000000..15b9b275d
--- /dev/null
+++ b/gemfiles/rails_6.0.gemfile
@@ -0,0 +1,7 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "rails", "~> 6.0.0"
+
+gemspec path: "../"
diff --git a/gemfiles/rails_6.0.gemfile.lock b/gemfiles/rails_6.0.gemfile.lock
new file mode 100644
index 000000000..8787736ef
--- /dev/null
+++ b/gemfiles/rails_6.0.gemfile.lock
@@ -0,0 +1,200 @@
+PATH
+  remote: ..
+  specs:
+    good_job (0.2.0)
+      concurrent-ruby (>= 1.0.2)
+      rails (>= 5.1.0)
+      thor (>= 0.14.1)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    actioncable (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      nio4r (~> 2.0)
+      websocket-driver (>= 0.6.1)
+    actionmailbox (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activejob (= 6.0.2.1)
+      activerecord (= 6.0.2.1)
+      activestorage (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      mail (>= 2.7.1)
+    actionmailer (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      actionview (= 6.0.2.1)
+      activejob (= 6.0.2.1)
+      mail (~> 2.5, >= 2.5.4)
+      rails-dom-testing (~> 2.0)
+    actionpack (6.0.2.1)
+      actionview (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      rack (~> 2.0, >= 2.0.8)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.2.0)
+    actiontext (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activerecord (= 6.0.2.1)
+      activestorage (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      nokogiri (>= 1.8.5)
+    actionview (6.0.2.1)
+      activesupport (= 6.0.2.1)
+      builder (~> 3.1)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.1, >= 1.2.0)
+    activejob (6.0.2.1)
+      activesupport (= 6.0.2.1)
+      globalid (>= 0.3.6)
+    activemodel (6.0.2.1)
+      activesupport (= 6.0.2.1)
+    activerecord (6.0.2.1)
+      activemodel (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+    activestorage (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activejob (= 6.0.2.1)
+      activerecord (= 6.0.2.1)
+      marcel (~> 0.3.1)
+    activesupport (6.0.2.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+      zeitwerk (~> 2.2)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
+    appraisal (2.2.0)
+      bundler
+      rake
+      thor (>= 0.14.0)
+    builder (3.2.4)
+    concurrent-ruby (1.1.6)
+    crass (1.0.6)
+    database_cleaner (1.8.3)
+    diff-lcs (1.3)
+    erubi (1.9.0)
+    faraday (0.17.3)
+      multipart-post (>= 1.2, < 3)
+    faraday-http-cache (2.0.0)
+      faraday (~> 0.8)
+    gem-release (2.1.1)
+    github_changelog_generator (1.15.0)
+      activesupport
+      faraday-http-cache
+      multi_json
+      octokit (~> 4.6)
+      rainbow (>= 2.2.1)
+      rake (>= 10.0)
+      retriable (~> 3.0)
+    globalid (0.4.2)
+      activesupport (>= 4.2.0)
+    i18n (1.8.2)
+      concurrent-ruby (~> 1.0)
+    loofah (2.4.0)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.5.9)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    marcel (0.3.3)
+      mimemagic (~> 0.3.2)
+    method_source (0.9.2)
+    mimemagic (0.3.4)
+    mini_mime (1.0.2)
+    mini_portile2 (2.4.0)
+    minitest (5.14.0)
+    multi_json (1.14.1)
+    multipart-post (2.1.1)
+    nio4r (2.5.2)
+    nokogiri (1.10.9)
+      mini_portile2 (~> 2.4.0)
+    octokit (4.16.0)
+      faraday (>= 0.9)
+      sawyer (~> 0.8.0, >= 0.5.3)
+    pg (1.2.2)
+    public_suffix (4.0.3)
+    rack (2.2.2)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails (6.0.2.1)
+      actioncable (= 6.0.2.1)
+      actionmailbox (= 6.0.2.1)
+      actionmailer (= 6.0.2.1)
+      actionpack (= 6.0.2.1)
+      actiontext (= 6.0.2.1)
+      actionview (= 6.0.2.1)
+      activejob (= 6.0.2.1)
+      activemodel (= 6.0.2.1)
+      activerecord (= 6.0.2.1)
+      activestorage (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      bundler (>= 1.3.0)
+      railties (= 6.0.2.1)
+      sprockets-rails (>= 2.0.0)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
+    railties (6.0.2.1)
+      actionpack (= 6.0.2.1)
+      activesupport (= 6.0.2.1)
+      method_source
+      rake (>= 0.8.7)
+      thor (>= 0.20.3, < 2.0)
+    rainbow (3.0.0)
+    rake (13.0.1)
+    retriable (3.1.2)
+    rspec-core (3.9.1)
+      rspec-support (~> 3.9.1)
+    rspec-expectations (3.9.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-mocks (3.9.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-rails (3.9.0)
+      actionpack (>= 3.0)
+      activesupport (>= 3.0)
+      railties (>= 3.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.2)
+    sawyer (0.8.2)
+      addressable (>= 2.3.5)
+      faraday (> 0.8, < 2.0)
+    sprockets (4.0.0)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
+    sprockets-rails (3.2.1)
+      actionpack (>= 4.0)
+      activesupport (>= 4.0)
+      sprockets (>= 3.0.0)
+    thor (1.0.1)
+    thread_safe (0.3.6)
+    tzinfo (1.2.6)
+      thread_safe (~> 0.1)
+    websocket-driver (0.7.1)
+      websocket-extensions (>= 0.1.0)
+    websocket-extensions (0.1.4)
+    zeitwerk (2.3.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  appraisal
+  database_cleaner
+  gem-release
+  github_changelog_generator
+  good_job!
+  pg
+  rails (~> 6.0.0)
+  rspec-rails
+
+BUNDLED WITH
+   2.1.2
diff --git a/good_job.gemspec b/good_job.gemspec
index b5328b2dd..be82422b1 100644
--- a/good_job.gemspec
+++ b/good_job.gemspec
@@ -17,9 +17,10 @@ Gem::Specification.new do |spec|
   spec.files = Dir["{lib}/**/*", "bin/good_job", "LICENSE.txt", "README.md"]
   spec.executables = "good_job"
 
-  spec.add_dependency "concurrent-ruby"
-  spec.add_dependency "rails"
-  spec.add_dependency "thor"
+  spec.add_dependency "concurrent-ruby", ">= 1.0.2"
+  spec.add_dependency "rails", ">= 5.1.0"
+  spec.add_dependency "thor", ">= 0.14.1"
+  spec.add_development_dependency "appraisal"
   spec.add_development_dependency "database_cleaner"
   spec.add_development_dependency "gem-release"
   spec.add_development_dependency "github_changelog_generator"
diff --git a/lib/good_job/lockable.rb b/lib/good_job/lockable.rb
index b484ac45e..d6ff9e331 100644
--- a/lib/good_job/lockable.rb
+++ b/lib/good_job/lockable.rb
@@ -42,7 +42,7 @@ def self.advisory_lock_details
       end
 
       def advisory_lock
-        self.class.connection.execute(self.class.sanitize_sql_for_conditions(["SELECT 1 as one WHERE pg_try_advisory_lock(('x'||substr(md5(?), 1, 16))::bit(64)::bigint)", id])).ntuples > 0
+        self.class.connection.execute(sanitize_sql_for_conditions(["SELECT 1 as one WHERE pg_try_advisory_lock(('x'||substr(md5(?), 1, 16))::bit(64)::bigint)", id])).ntuples > 0
       end
 
       def advisory_lock!
@@ -92,6 +92,13 @@ def advisory_unlock
       def advisory_unlock!
         advisory_unlock while advisory_locked?
       end
+
+      private
+
+      def sanitize_sql_for_conditions(*args)
+        # Made public in Rails 5.2
+        self.class.send(:sanitize_sql_for_conditions, *args)
+      end
     end
   end
 end
diff --git a/spec/dummy/app/assets/images/.keep b/spec/dummy/app/assets/images/.keep
deleted file mode 100644
index e69de29bb..000000000
diff --git a/spec/dummy/config/application.rb b/spec/dummy/config/application.rb
index a4e0f9698..9356e4356 100644
--- a/spec/dummy/config/application.rb
+++ b/spec/dummy/config/application.rb
@@ -8,7 +8,7 @@
 module Dummy
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
-    config.load_defaults 6.0
+    # config.load_defaults 6.0
 
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration can go into files in config/initializers
diff --git a/spec/dummy/config/environments/test.rb b/spec/dummy/config/environments/test.rb
index 1d62e91b3..80cef5627 100644
--- a/spec/dummy/config/environments/test.rb
+++ b/spec/dummy/config/environments/test.rb
@@ -4,45 +4,6 @@
 # and recreated between test runs. Don't rely on the data there!
 
 Rails.application.configure do
-  # Settings specified here will take precedence over those in config/application.rb.
-
   config.cache_classes = false
-
-  # Do not eager load code on boot. This avoids loading your whole application
-  # just for the purpose of running a single test. If you are using a tool that
-  # preloads Rails for running tests, you may have to set it to true.
   config.eager_load = false
-
-  # Configure public file server for tests with Cache-Control for performance.
-  config.public_file_server.enabled = true
-  config.public_file_server.headers = {
-    'Cache-Control' => "public, max-age=#{1.hour.to_i}"
-  }
-
-  # Show full error reports and disable caching.
-  config.consider_all_requests_local       = true
-  config.action_controller.perform_caching = false
-  config.cache_store = :null_store
-
-  # Raise exceptions instead of rendering exception templates.
-  config.action_dispatch.show_exceptions = false
-
-  # Disable request forgery protection in test environment.
-  config.action_controller.allow_forgery_protection = false
-
-  # Store uploaded files on the local file system in a temporary directory.
-  config.active_storage.service = :test
-
-  config.action_mailer.perform_caching = false
-
-  # Tell Action Mailer not to deliver emails to the real world.
-  # The :test delivery method accumulates sent emails in the
-  # ActionMailer::Base.deliveries array.
-  config.action_mailer.delivery_method = :test
-
-  # Print deprecation notices to the stderr.
-  config.active_support.deprecation = :stderr
-
-  # Raises error for missing translations.
-  # config.action_view.raise_on_missing_translations = true
 end