If we don't get a display_num in Xvfb, find a suitable one
Add logging to backend creation
Merge pull request #25 from ant1441/xvfb-auto-file

Xvfb auto file
Add travis-ci config & fix dep versions
Merge pull request #26 from ant1441/travis-ci

Add travis-ci config & fix dep versions
Rename .travis.yaml to .travis.yml