bug fix

rowers/models.py

@@ -6,6 +6,7 @@ from __future__ import unicode_literals, absolute_import
 
 from django.utils.encoding import python_2_unicode_compatible
 
+from django.db import models,IntegrityError
 from django.contrib.auth.models import User
 from django.core.validators import validate_email
 from django.core.exceptions import ValidationError