Initial commit for Postgres Operator UI (#613)

* Initial commit for our basic Postgres Operator UI:
 * Create and modify Postgres manifests
 * Watch Operator Logs in the UI
 * Observe cluster creation progress
 * S3 Backup browser for clone and restore

Many thanks to Manuel Gomez and Jan Mussler for the initial UI work a long time ago!

ui/operator_ui/update.py

@@ -0,0 +1,12 @@
+import logging
+import time
+
+import gevent
+import json_delta
+import requests.exceptions
+
+from .backoff import expo, random_jitter
+from .utils import get_short_error_message
+
+logger = logging.getLogger(__name__)
+