appraise '3.0' do gem 'rails', '~> 3.0.0' end appraise '3.1' do gem 'rails', '~> 3.1.0' end appraise '3.2' do gem 'rails', '~> 3.2.0' end appraise '4.0' do gem 'rails', '~> 4.0.0' end appraise '4.1' do gem 'rails', '~> 4.1.0' end appraise '4.2' do gem 'rails', '~> 4.2.0' end