appraise "rails-42" do gem "rails", "~> 4.2.0" gem "rspec", "~> 3.4.0" end appraise "rails-42-rspec-33" do gem "rails", "~> 4.2.0" gem "rspec", "~> 3.3.0" end appraise "rails-5" do gem "rails", "~> 5.0.0.beta2" gem "rspec", "~> 3.5.0.beta1" end