Whitespace cleanup.

* Removed trailing whitespace.
* Added newline to EOF if missing.
* Removed blank lines at EOF.
* Removed some stray tabs.

tests/validation/test_unique.py

@@ -141,4 +141,3 @@ class PerformUniqueChecksTest(TestCase):
         with self.assertRaises(ValidationError) as cm:
             m.full_clean()
         self.assertEqual(cm.exception.message_dict, {'no': ['Custom unique number message.']})
-