Cleanup of User class
[Issues #75] Initial commit for API key

- Implementation Based off AWS REST API
- User creation generates a unique API Key and Client Secret
- Signature generated using selected header values
- Added api fields to Account models
[Issues #75] Added test for apikey generation on registration
[Issue #72][Issue #75] Added decorator to validate api based signature on request. Fallback is basic auth.
[Issue #72][Issue #75] Consuming api based auth in v2 json submission