Add PyPy and Python 3.4 to the Travis CI build

 * PyPy/Pillow requires tkinter.

 * Python 3.4 added as an allowed failure. It will soon be added to Travis CI: https://github.com/travis-ci/travis-ci/issues/1989

I cherry-picked the README link of examples, I don't think this should overwrite your build badges.

Passing build: https://travis-ci.org/hugovk/wallpaperfm/builds/21573507