Created an endpoint to test how the incoming messages from MMG will work.

So this just prints the response to logs, removing the phone number first. Then returns the requested RECEIVED.

app/__init__.py

@@ -123,6 +123,7 @@ def init_app(app):
             url_for('notifications.process_ses_response'),
             url_for('notifications.process_firetext_response'),
             url_for('notifications.process_mmg_response'),
+            url_for('notifications.receive_mmg_sms'),
             url_for('status.show_delivery_status'),
             url_for('spec.get_spec')
         ]