Add some docstrings and comments

cas_server/apps.py

@@ -1,7 +1,9 @@
+"""django config module"""
 from django.utils.translation import ugettext_lazy as _
 from django.apps import AppConfig
 
 
 class CasAppConfig(AppConfig):
+    """django CAS application config class"""
     name = 'cas_server'
     verbose_name = _('Central Authentication Service')