appraise 'rails-3.0' do
  gem 'rails',      '~> 3.0.0'
end

appraise 'rails-3.1' do
  gem 'rails',      '~> 3.1.0'
end

appraise 'rails-3.2' do
  gem 'rails',      '~> 3.2.0'
end

appraise 'rails-4.0' do
  gem 'rails',      '~> 4.0'
end