Fix missing comma...

Author: Surgo

lookup_extensions/sql.py

@@ -4,7 +4,7 @@
 from django.db.models.sql import Query as DjangoQuery
 
 
-class ExtendedQueryMixin(object)
+class ExtendedQueryMixin(object):
     SUBQUERY_LOOKUPS = (
         'exists',
         'neexists',