Added Rubinius 1.9 mode to .travis.yml

I see 5 failures on the 2nd set of specs under Rubinius. Haven't investigated whether it's Rubinius or the specs yet. So, I've set Travis to ignore failures on Rubinius for the time being.
Merge pull request #33 from brixen/patch-1

Added Rubinius 1.9 mode to .travis.yml