Made SMS messages go through celery

- twilio client pulled in from delivery app
- made method to perform task

run_celery.py

@@ -1,7 +1,6 @@
 #!/usr/bin/env python
 import os
 from app import celery, create_app
-from app.celery.tasks import refresh_services
 
 application = create_app(os.getenv('NOTIFY_API_ENVIRONMENT') or 'development')
 application.app_context().push()