Update urllib/httplib/cStringIO to use six.moves

partial blueprint heat-python34-support

Change-Id: I00a7064560a95a33dcb1e621961765822d4e94d4
diff --git a/scenario/test_neutron_loadbalancer.py b/scenario/test_neutron_loadbalancer.py
index fafa9be..1cb1c6f 100644
--- a/scenario/test_neutron_loadbalancer.py
+++ b/scenario/test_neutron_loadbalancer.py
@@ -12,7 +12,8 @@
 #    under the License.
 
 import time
-import urllib
+
+from six.moves import urllib
 
 from heat_integrationtests.scenario import scenario_base
 
@@ -31,7 +32,7 @@
         resp = set()
         for count in range(10):
             time.sleep(1)
-            resp.add(urllib.urlopen('http://%s/' % ip).read())
+            resp.add(urllib.request.urlopen('http://%s/' % ip).read())
 
         self.assertEqual(expected_resp, resp)