minor: Import reduce.

abawchen · abawchen · commit 23b8dc4790a6 · 2018-01-31T22:30:09.000+08:00
diff --git a/graphene_mongo/fields.py b/graphene_mongo/fields.py
@@ -1,7 +1,7 @@
 from __future__ import absolute_import
 
 from collections import OrderedDict
-from functools import partial
+from functools import partial, reduce
 
 from graphene import Field
 from graphene.relay import ConnectionField
