refactor auth file to also allow the DATABASE_URL variable

Author: MoralCode

auth.py

@@ -9,16 +9,11 @@
 db_host = os.getenv("DB_HOST", "localhost")
 db_name = os.getenv("DB_NAME", "classclock")
 
+connection_url = f'mysql+mysqlconnector://{db_username}:{db_password}@{db_host}/{db_name}?charset=utf8mb4&collation=utf8mb4_general_ci'
+db_connection_string = os.getenv("DB_CONNECTION_URL", connection_url)
 
+db_connection_string = os.getenv("DATABASE_URL", connection_url)
 
-db_connection_string=os.getenv("DB_CONNECTION_URL", 
-    'mysql+mysqlconnector://{user}:{pw}@{url}/{db}?charset=utf8mb4&collation=utf8mb4_general_ci'.format(
-        user=db_username,
-        pw=db_password,
-        url=db_host,
-        db=db_name
-    )
-)
 # elif sys.argv[1] == "demo":
 # # https://stackoverflow.com/a/46541219
 #     with app.app_context():