Move cord-tester voltha rest interface to use envoy.
Plus other misc. changes

Change-Id: I03c40841ef07d9c0523799dc2efbd7e0caa1e536
diff --git a/src/test/voltha/volthaTest.py b/src/test/voltha/volthaTest.py
index 4cced32..39de312 100644
--- a/src/test/voltha/volthaTest.py
+++ b/src/test/voltha/volthaTest.py
@@ -213,7 +213,7 @@
     OLT_MAC = '00:0c:e2:31:12:00'
     VOLTHA_HOST = VolthaService.DOCKER_HOST_IP
     VOLTHA_PONSIM_HOST = VolthaService.PONSIM_HOST
-    VOLTHA_REST_PORT = 8881
+    VOLTHA_REST_PORT = VolthaCtrl.REST_PORT
     VOLTHA_OLT_TYPE = 'ponsim_olt'
     VOLTHA_OLT_MAC = '00:0c:e2:31:12:00'
     VOLTHA_IGMP_ITERATIONS = 100