Initial draft for DeviceController.
Add dep on authbucket/oauth2.
Sync some basic implementation with authbucket/oauth2.
Prepare the fake /oauth2/debug endpoint for dev.
Simplify tests/src/ as tests/.
Add simplified oauth2 debug endpoint implementation for testing.
Merge branch 'feature/DeviceController' into develop
Draft for Model/ServiceInterface.
Rename table with authbucket_push_ prefix.
Add ServiceFixture.
Prepare to migrate DeviceController's implementation to specific ServiceTypeHandler.
Initially migrate DebugController to specific ServiceTypeHandler.
DeviceController now act as proxy to specific supported ServiceTypeHandler.
Rename device_id as device_token.
Merge branch 'feature/Service' into develop
Merge branch 'develop'