Add stub for a custom User model.

biscuit/core/models.py

+from django.contrib.auth.models import AbstractUser
+from django.db import models
+
+
+class Person(AbstractUser):
+    pass
+ 
\ No newline at end of file

biscuit/core/settings.py

@@ -102,3 +102,5 @@ USE_TZ = True
 # https://docs.djangoproject.com/en/2.1/howto/static-files/
 
 STATIC_URL = '/static/'
+
+AUTH_USER_MODEL = 'biscuit.core.models.Person'