Fixed database connection issue

ref-test/app/__init__.py

@@ -1,4 +1,8 @@
-from .modules import bootstrap, csrf, db, login_manager, mail
+from .modules.bootstrap import bootstrap
+from .modules.csrf import csrf
+from .modules.db import db
+from .modules.login_manager import login_manager
+from .modules.mail import mail
 from .config import DevelopmentConfig as Config
 
 from flask import Flask