Remove unnecessary dirs
Working tests in a mock Laravel app environment

Still needs a bit of refinement, but we have a working test rig.

- The 'posts' table should be created and dropped for each test case, allowing
  custom fields for some tests (like CustomBlameableTest),
- Might flesh out the in-memory configuration loader and push back to Laravel,
- Is $app->singleton correct, or should it be $app->share (I think singleton
  allows access via the Facades).