Tidy setup.py (#376)
Tidy setup.py (#376)

* Remove 'platforms' argument which is free-form and not used on any of my other maintained packages ( https://stackoverflow.com/questions/34994130/what-does-the-platforms-argument-to-setup-in-setup-py-do )
* Make 'keywords' a list
ottoyiu/django-cors-headers,ottoyiu/django-cors-headers