appraise "rails-4.1" do gem "rails", "~> 4.1.0" end 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