Add utility function for subscription autoconfirm

app/notifications/utils.py

@@ -0,0 +1,8 @@
+import requests
+
+
+def confirm_subscription(confirmation_request):
+    url = confirmation_request['SubscribeURL']
+    response = requests.get(url)
+    if response.code < 400:
+        return confirmation_request['TopicArn']