Add TODO to release the gems before the next Rails release

Gemfile

@@ -8,10 +8,15 @@ gemspec
 gem 'mocha', '~> 0.14', require: false
 
 gem 'rack-cache', '~> 1.2'
+# TODO: Release this gem
 gem 'jquery-rails', github: 'rails/jquery-rails', branch: 'master'
 gem 'coffee-rails', '~> 4.0.0'
+# TODO: Release this gem
 gem 'rails-html-sanitizer', github: 'rails/rails-html-sanitizer'
+# TODO: Release this gem
 gem 'rails-deprecated_sanitizer', github: 'rails/rails-deprecated_sanitizer'
+# TODO: Release this gem
+gem 'rails-dom-testing', github: 'rails/rails-dom-testing'
 gem 'turbolinks', '~> 2.2.3'
 
 # require: false so bcrypt is loaded only when has_secure_password is used.