Gemfile in active_model_serializers-0.10.0.rc3 vs Gemfile in active_model_serializers-0.10.0.rc4

@@ -9,40 +9,41 @@
 
 version = ENV['RAILS_VERSION'] || '4.2'
 
 if version == 'master'
   gem 'rack', github: 'rack/rack'
+  gem 'arel', github: 'rails/arel'
   git 'https://github.com/rails/rails.git' do
     gem 'railties'
     gem 'activesupport'
     gem 'activemodel'
     gem 'actionpack'
+    gem 'activerecord', group: :test
     # Rails 5
     gem 'actionview'
   end
-  # Rails 5
-  gem 'rails-controller-testing', github: 'rails/rails-controller-testing'
 else
   gem_version = "~> #{version}.0"
   gem 'railties', gem_version
   gem 'activesupport', gem_version
   gem 'activemodel', gem_version
   gem 'actionpack', gem_version
+  gem 'activerecord', gem_version, group: :test
 end
 
+# https://github.com/bundler/bundler/blob/89a8778c19269561926cea172acdcda241d26d23/lib/bundler/dependency.rb#L30-L54
+@windows_platforms = [:mswin, :mingw, :x64_mingw]
+
+# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
+gem 'tzinfo-data', platforms: (@windows_platforms + [:jruby])
+
 group :test do
-  gem 'activerecord'
-  gem 'sqlite3', platform: [:ruby, :mingw, :x64_mingw, :mswin]
+  gem 'sqlite3',                          platform: (@windows_platforms + [:ruby])
   gem 'activerecord-jdbcsqlite3-adapter', platform: :jruby
+
   gem 'codeclimate-test-reporter', require: false
+  gem 'simplecov', '~> 0.10', require: false, group: :development
 end
-
-group :test, :development do
-  gem 'simplecov', '~> 0.10', require: false
-end
-
-# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
-gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
 
 group :development, :test do
   gem 'rubocop', '~> 0.34.0', require: false
 end