appraise "4.2" do gem "rails", "~> 4.2" end appraise "5.0" do gem "rails", "~> 5.0" end appraise "5.1" do gem "rails", "~> 5.1" end appraise "5.2" do gem "rails", "~> 5.2" end appraise "6.0" do gem 'rails', '~> 6.0.0.beta3' end