WTF: tests fail if I run locally

in util/image.py we try to set a string into a byte object
in ext/freetype.py (line 36) we are using `.encode('utf-8')
on a byte object.

Maybe this is because I use Python 3.4?
Make Travis use Py 3.4 instead of 3.3

I just replaced all occurances of "3.3" with "3.4" in
travis.yml. I also checked that there are no occurances
of "33". I hope this is all there's to it.
Fix error in find_font() on Py3k Linux
Merge pull request #364 from almarklein/test-fail-py3k

Make Travis use py 3.4 + fix in find_font