This patch is a subset of:
https://github.com/datadriventests/ddt/pull/74

Not all the files touched by the pull request are in the PyPI sdist, so
those chunks have been removed.

diff --git a/test/test_functional.py b/test/test_functional.py
index 5049928..9275ffc 100644
--- a/test/test_functional.py
+++ b/test/test_functional.py
@@ -2,7 +2,10 @@
 import json
 
 import six
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 from ddt import ddt, data, file_data
 from nose.tools import (