Update quay sec code to fix problems identified in previous review

- Change get_repository_images_recursive to operate over a single docker image and storage uuid
- Move endpoints/sec to endpoints/secscan
- Change notification system to work with new Quay-sec format

Fixes #768

endpoints/api/secscan.py

@@ -18,7 +18,7 @@ logger = logging.getLogger(__name__)
 def _call_security_api(relative_url, *args, **kwargs):
   """ Issues an HTTP call to the sec API at the given relative URL. """
   try:
-    response = secscan_endpoint.call_api(relative_url, *args, **kwargs)
+    response = secscan_endpoint.call_api(relative_url, body=None, *args, **kwargs)
   except requests.exceptions.Timeout:
     raise DownstreamIssue(payload=dict(message='API call timed out'))
   except requests.exceptions.ConnectionError: