Fixing up tests to validate the call to the celery tasks.

- mocker used to test call or otherwise of the task
- no new tests just a spring clean

run_celery.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 import os
-from app import celery, create_app
+from app import notify_celery, create_app
 
 application = create_app(os.getenv('NOTIFY_API_ENVIRONMENT') or 'development')
 application.app_context().push()