Add isort & flake8 settings.
Add isort & flake8 settings.

django-json-api/django-rest-framework-json-api,Instawork/django-rest-framework-json-api,leo-naeka/django-rest-framework-json-api,django-json-api/django-rest-framework-json-api,abdulhaq-e/django-rest-framework-json-api,django-json-api/rest_framework_ember