Django 1.10 middleware

[joncombe]

Great work, Mr Weber.

I found an issue though, the code isn't currently compatible with the recent change to middleware in Django 1.10.

I'm sorry, I don't have time today to submit a pull request but to fix it, 1) add from django.utils.deprecation import MiddlewareMixin to the top of the middleware.py file and 2) change class JWTAuthMiddleware(object): to class JWTAuthMiddleware(MiddlewareMixin):. That's it. It should be backward compatible but I haven't had chance to test it.