I'm having trouble keeping my users logged in with the auth cookie.
Is the cookie's expiration time the only factor for it's validity?
Here's what I'm trying now for my config:
# webapp2 config
app_config = {
    'webapp2_extras.sessions': {
        'secret_key': settings.SESSION_KEY
    },
    'webapp2_extras.auth': {
        'user_attributes': [],
        'session_backend': 'datastore',
        'token_max_age': 86400 * 7 * 500  # aka forever
    }
}