wip
Theme and version model + git adapter

Create models for f/e engine
Git storage adapter for theme_resolver
Fix redis implemenation of resolver

Add tests and ensure the redis resolver is more conformant to the rails
template resolver api.
Improve Theme publishing functionality.

Theme and theme Version objects now work correctly, interacting with the
git source object to retrieve the repo.

Theme and version models still need persistence.
Publisher needs fleshing out with:
  * middleware pattern
  * sync to resolver backend - redis
  * other middleware for:
    * asset_sync
    * locale reloading
    * config/settings integration
Add extra watch directive for minitest in Guard
Make redis storage resolver work and compliant