Rename create_app.py to app.py for Gunicorn command

auth.py

@@ -3,7 +3,7 @@ from flask_login import login_required, login_user, logout_user, current_user
 from werkzeug.security import check_password_hash, generate_password_hash
 
 from .models import User
-from .create_app import db
+from .app import db
 
 blueprint = Blueprint('auth', __name__)