Added lib-secret-manager which consumes secrets after application launch

src/send_notification.py

@@ -1,7 +1,7 @@
 import requests
 from requests.exceptions import RequestException, Timeout, ConnectionError, HTTPError
 from fastapi import HTTPException
-from secret_handler import return_credentials
+from secret_manager import return_credentials
 import os
 import time
 from simple_logger_handler import setup_logger