fix codestyle

Author: mdko

tests/test_transform.py

@@ -258,6 +258,7 @@ def test_replace_only_dst_wire(self):
         self.assertEqual(w4_dst_net.args, (w4, w2))
         self.assertEqual(w4_dst_net.dests, w1_dst_net.dests)
 
+
 class TestCloning(unittest.TestCase):
     def setUp(self):
         pyrtl.reset_working_block()