David/users in session

When using a custom user model in your CAS server, and passing it to your userless application with this cas client installed, any custom attributes on the user are lost (when accessed via the auth backends `get_user` method) as it constructs a vanilla contrib.auth user with the received data, to circumvent this problem I'm going to try and store the user somewhere other than the database, meaning i dont need to correlate my user model and db schema on both cas client and cas server...