make sure tests on travis runs and works

[ralphtheninja]

All repositories should have travis running and tests working. This might take some work though, I know too little on how the setup is for jxcore.

cc @obastemur

[ralphtheninja]

We could probably fix up .travis.yml so the proper environment is installed to make the tests run. This can also be good information for others wanting to run jxcore to see what's required. Maybe you have a use case where you want to include something else together with jxcore. Not sure if that's possible at all or how that would work but just thinking out loud :)