Add Travis-CI integration

This branch builds on my dummy-provider branch, adding a `.travis.yml` to run automatic integration builds on Travis. You guys at Puppet Labs would need to sign up for Travis to enable this to run on your behalf.

I highly recommend this service for all of your open-source code, and they are starting up a private-repo service that you can use to run tests for your enterprise products as well!

My Travis results are posted here: https://travis-ci.org/#!/sodabrew/puppetlabs-vcsrepo