Test all versions of rails supported
Add dependency of responders
Dummy application supports Rails4.x
Garage::OptionalResponseBodyResponder#api_behavior support Rails 4.2
Drop support of Rails 3.x
Use Rails::VERSION::{MAJOR,MINOR}
Remove feature branch from .travis.yml. [ci skip]
Merge pull request #10 from fortissimo1997/support_rails42

Support Rails 4.2 and drop support of Rails 3.x