make flake8 happy again

Author: maedoc

test/test_utils.py

@@ -818,6 +818,7 @@ def test_restore_cwd(self):
             after = os.getcwd()
         self.assertEqual(before, after)
 
+
 class FlattenTest(unittest.TestCase):
     def test_good(self):
         array_3d = np.empty((200, 4, 4))