Remove old Travis files

Signed-off-by: Ben Firshman <ben@firshman.co.uk>
Make script/test use Docker

Really easy to run entire test suite with Docker now. Also switch
Wercker to use the same script.

Signed-off-by: Ben Firshman <ben@firshman.co.uk>
Merge pull request #506 from bfirsh/make-test-script-use-docker

Make script/test use docker
Add versioneer

It's a clever versioning thing which means we don't have to manage
versions. It'll magically read the version from Git tags and
generate useful development version numbers.

https://github.com/warner/python-versioneer

Signed-off-by: Ben Firshman <ben@firshman.co.uk>