auth systems should always be present, even if not enabled, otherwise emails can fail

helios_auth/auth_systems/__init__.py

 from django.conf import settings
-
-_enabled = settings.AUTH_ENABLED_SYSTEMS or None
-def _is_enabled(system):
-    return _enabled is None or system in _enabled
+from . import password, twitter, linkedin, cas, facebook, google, yahoo, clever
 
 AUTH_SYSTEMS = {}
 
-if _is_enabled('twitter'):
-    from . import twitter
+AUTH_SYSTEMS['password'] = password
 AUTH_SYSTEMS['twitter'] = twitter
-
-if _is_enabled('linkedin'):
-    from . import linkedin
 AUTH_SYSTEMS['linkedin'] = linkedin
-
-if _is_enabled('password'):
-    from . import password
-    AUTH_SYSTEMS['password'] = password
-
-if _is_enabled('cas'):
-    from . import cas
 AUTH_SYSTEMS['cas'] = cas
-
-if _is_enabled('facebook'):
-    from . import facebook
 AUTH_SYSTEMS['facebook'] = facebook
-
-if _is_enabled('google'):
-    from . import google
 AUTH_SYSTEMS['google'] = google
-
-if _is_enabled('yahoo'):
-    from . import yahoo
 AUTH_SYSTEMS['yahoo'] = yahoo
-
-if _is_enabled('clever'):
-    from . import clever
 AUTH_SYSTEMS['clever'] = clever
 
 # not ready