appraise "rails-4-2" do
  gem 'rails', '~> 4.2.0'
end

appraise "rails-5-0" do
  gem 'rails', '~> 5.0.0'
end

appraise "rails-5-1" do
  gem 'rails', '~> 5.1.0'
end

appraise "rails-head" do
  gem 'rails', github: 'rails/rails'
end