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