add postgresql container to run tests in

backend/src/main.py

@@ -16,7 +16,14 @@ db_params = {
     'port': int(env.get('DB_PORT'))
 }
 
-db = psql.connect(**db_params)
+db = None
+
+for _ in range(5):
+    try:
+        db = psql.connect(**db_params)
+    except Exception as e:
+        print(f"Failed to connect ({e}), retrying...")
+        time.sleep(5)
 
 class PassQueue:
     def __init__(self):