Update Rubinius on Travis
Update Rubinius on Travis

Travis actually dropped (due to rvm dropping) support for rbx-1.8 and
rbx-1.9. There is now the option to have 2.2.1 and head. We should do
something about this.

AEgan/rspec-mocks,ducthanh/rspec-mocks,ducthanh/rspec-mocks,rwz/rspec-mocks,AEgan/rspec-mocks,h4ck3rm1k3/rspec-mocks,maclover7/rspec-mocks,rspec/rspec-mocks,rwz/rspec-mocks,telekomatrix/rspec-mocks,edwardpark/rspec-mocks,telekomatrix/rspec-mocks,maclover7/rspec-mocks,h4ck3rm1k3/rspec-mocks,rspec/rspec-mocks,zephyr-dev/rspec-mocks,zephyr-dev/rspec-mocks,edwardpark/rspec-mocks