Update to channels 4.0.0

• update setup.py and test dependencies to channels 4.0.0
• add async examples to tests and tutorial

Drf query string tokens

Added middlewares

1. QueryStringDRFAuthTokenMiddleware
2. QueryStringSimpleJWTAuthTokenMiddleware

Added middleware stacks

1. DRFAuthTokenMiddlewareStack
2. SimpleJWTAuthTokenMiddlewareStack

Non lowercase headers

Add non lowercase headers handle.

Initial

Features

• Django REST framework token authentication middleware
• Simple JWT middleware
• Easily extendable middlewares to work with auth tokens placed in request headers, cookie and query string