Minimal working version

* Upgrade dependencies
* Fix ugettext
* Fix bad urls

core/models.py

@@ -34,7 +34,7 @@ from django.contrib.auth.models import (
     GroupManager as AuthGroupManager,
     AnonymousUser as AuthAnonymousUser,
 )
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import gettext_lazy as _
 from django.utils import timezone
 from django.core import validators
 from django.core.exceptions import ValidationError, PermissionDenied