Have every class inherit from object.

evennia/server/models.py

@@ -8,6 +8,8 @@ Config values should usually be set through the
 manager's conf() method.
 
 """
+from builtins import object
+
 try:
     import cPickle as pickle
 except ImportError:
@@ -99,7 +101,7 @@ class ServerConfig(WeakSharedMemoryModel):
         self.delete()
     value = property(__value_get, __value_set, __value_del)
 
-    class Meta:
+    class Meta(object):
         "Define Django meta options"
         verbose_name = "Server Config value"
         verbose_name_plural = "Server Config values"