VOL-572: Integration testing with Kubernetes

* Updated the Kubernetes version installed in the single-node environment from 1.8.5 to 1.9.3.
* Replaced the Weave pod network plugin with Calico
* Updated test_device_state_changes to run in single-node Kubernetes
* Moved test_utils.py from voltha/tests/itests/docutests/ to voltha/tests/itests/.

Change-Id: I472cffec1e0c3a783edaecb375664cd1c6bb93b1
diff --git a/k8s/single-node/vcore_for_etcd.yml b/k8s/single-node/vcore_for_etcd.yml
index ff579dc..fb75ee7 100644
--- a/k8s/single-node/vcore_for_etcd.yml
+++ b/k8s/single-node/vcore_for_etcd.yml
@@ -52,7 +52,7 @@
             - "--interface=eth1"
             - "--backend=etcd"
             - "--pon-subnet=10.38.0.0/12"
-#            - "--ponsim-comm=grpc"
+            - "--ponsim-comm=grpc"
           ports:
             - containerPort: 8880
               name: rest-port