Add development dep yard-junk and Rake task lint:yard:junk

Gemfile

@@ -44,6 +44,13 @@ group :development, :test do
   # Code Coverage
   gem 'simplecov', '~> 0.10'
 
+  # API docs generation
+  gem 'yard', '~>0.9.9'
+
+  if RUBY_VERSION >= '2.3.0'
+    gem 'yard-junk', '~> 0'
+  end
+
   # Test api
   gem 'rspec', '~> 3.4'
   gem 'fuubar', '~> 2.2.0'

Rakefile

@@ -72,6 +72,13 @@ namespace :lint do
   task :licenses do
     sh 'bundle exec license_finder'
   end
+
+  begin
+    require 'yard-junk/rake'
+    YardJunk::Rake.define_task
+  rescue LoadError # rubocop:disable Lint/HandleExceptions
+    # Not an issue; this lint tool requires Ruby 2.3+
+  end
 end
 
 namespace :rubygem do