Gemfile in active_model_serializers-0.8.3 vs Gemfile in active_model_serializers-0.8.4

@@ -1,4 +1,38 @@
 source 'https://rubygems.org'
 
 # Specify gem dependencies in active_model_serializers.gemspec
 gemspec
+
+version = ENV['RAILS_VERSION'] || '4.0'
+
+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
+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])
+
+# JRuby versions before 9.x report their version as "1.9.x" or lower, so lock these to an older version of mime-types
+if defined?(JRUBY_VERSION) and Gem::ruby_version < Gem::Version.new("2.0.0")
+  gem 'mime-types', '< 3'
+end