Remove usage of six

Remove six-library Replace the following items with Python 3 style code.
- six.moves

Change-Id: Ied212eb0947c7441cc51193399185b4fb0f87271
diff --git a/tempest/cmd/cleanup_service.py b/tempest/cmd/cleanup_service.py
index 84d2492..f2370f3 100644
--- a/tempest/cmd/cleanup_service.py
+++ b/tempest/cmd/cleanup_service.py
@@ -12,8 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from urllib import parse as urllib
+
 from oslo_log import log as logging
-from six.moves.urllib import parse as urllib
 
 from tempest import clients
 from tempest.common import credentials_factory as credentials