Fix URLs

The latest changes in URLs module breaks on any project with django<=1.6

Below lines
https://github.com/incuna/incuna-auth/blob/master/incuna_auth/urls.py#L21-22
need to wrap the urls in try/catch, or check for django version installed and add correct urls for each version of Django.

Also, seems like those https://github.com/incuna/incuna-auth/blob/master/incuna_auth/urls.py#L23-26 are duplicated...