Changed Django WSGI Middleware to workable Example

The previous code, `django.core.handlers.wsgi.WSGIHandler()`, did not work, even after `import django`
Merge pull request #274 from saulshanabrook/patch-1

Changed Django WSGI Middleware to workable Example
Merge pull request #273 from hodgestar/master

Add support for rate-limiting failing asynchronous requests made by TwistedHTTPTransport
Small change to let you pass dsn into init_app
Merge pull request #275 from TkTech/master

Small change to init_app() to allow passing the dns