* Fix: OneToOneRel, used by OneToOneField doesn't have help_text nor primary_key attributes, thus breaking OpenAPISchemaGenerator; use hasattr() as safe-guard.
* Fix: use getattr() with a default value instead of hasattr() + acessing the value
* Add: 'people' app that breaks drf_yasg without previous commits
* Update tests/references.yaml + run isort and flake8
* Fix: set on_delete for Person.identity as Django-2+ requires it
309a6eb8cd