[fix] imports

frappe/model/utils/rename_field.py

@@ -1,3 +1,11 @@
+# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
+# MIT License. See license.txt
+
+from __future__ import unicode_literals
+
+import frappe
+import json
+
 def rename_field(doctype, old_fieldname, new_fieldname):
 	"""This functions assumes that doctype is already synced"""