Don't need to be that 'on the edge' for now
Experiment with Travis
Travis config for Rubinius and Ruby 1.9.3.
rbx and rbx-2.0 both alias to Rubinius master.
Restore rubinius in .travis.yml
Revert the changes in 954cf7b.
Temporary disable jruby because it is not working on Travis.
Remove Rubinius from Travis config.
It continues to raise the error `call/cc is not implemented!`.
Enable Travis CI