Integration tests for buffalo plugins, examples, etc…

There needs to be a set of integration tests that, at the very least, run he tests for all “gobuffalo” packages, including example apps like toodo, and plugins such as buffalo-auth.

A bonus feature would be to run some integration tests with some of these packages and examples.

These integration tests should, at the very least, be run on release, but it would be great to get Travis doing them.