Fix pep8 failures seen on submitted patches

Seems like with some possible change in infra we see some
pep8 failures. These are related to Python 3 checks. Handling these
so that code is functional in either Python 2.7 or Python 3 envs.
An attempt is made to be in line with handling this in other community
projects.

Change-Id: Iec4c919bebb70365f932f23b926aa80bf4da6048

gbpservice/neutron/tests/unit/services/sfc/test_aim_sfc_driver.py

@@ -35,6 +35,10 @@ from gbpservice.neutron.tests.unit.services.grouppolicy import (
 
 LOG = logging.getLogger(__name__)
 
+import six
+if six.PY3:
+    from importlib import reload
+
 
 class Rollback(Exception):
     pass