rvm does not have 'rbx-XYZ-mode' anymore

Builds are failing on Travis CI because it cannot install this version. Unfortunately, it looks like you can't install 1.9.x versions of rubinius through rvm.

More info available at https://github.com/travis-ci/travis-ci/issues/1641
Merge pull request #183 from tjarratt/master

rvm does not have 'rbx-XYZ-mode' anymore

still needs some modifications to get green specs with rbx 2