Django: Changing User Model in Mid-Project
- https://www.caktusgroup.com/blog/2019/04/26/how-switch-custom-django-user-model-mid-project/
- https://ruddra.com/posts/django-custom-user-migration-mid-phase-project/
- https://code.djangoproject.com/ticket/25313
- https://docs.djangoproject.com/en/2.2/topics/auth/customizing/#extending-the-existing-user-model