Implement RuboCop

.github/workflows/test.yml

@@ -1,13 +1,28 @@
 name: Test
 
 on:
-  - pull_request
-  - push
+  pull_request: {}
+  push:
+    branches:
+      - master
 
 env:
   BUNDLE_WITHOUT: release
 
 jobs:
+  rubocop:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install Ruby ${{ matrix.ruby }}
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.0"
+          bundler-cache: true
+      - name: Run Rubocop
+        run: bundle exec rake rubocop
+
+
   rspec:
     runs-on: ubuntu-latest
     strategy:

.rubocop.yml

@@ -0,0 +1,23 @@
+---
+inherit_from: .rubocop_todo.yml
+
+require:
+  - rubocop-performance
+  - rubocop-rake
+  - rubocop-rspec
+
+AllCops:
+  TargetRubyVersion: 2.4
+  NewCops: enable
+
+Style/HashSyntax:
+  Enabled: false
+
+Metrics:
+  Enabled: false
+
+Style:
+  Enabled: false
+
+Layout:
+  Enabled: false