etcd cluster chart and usage in voltha requirements

Addition of a chart dedicated to creating etcdCluster CRD instances from an already installed etcd-operator
This is good for specifying custom etcd images, retention periods, and custom repo locations.
Also helpful in installing instances of an etcdCluster separate from installing etcd-operator

Modify the voltha chart to require the etcd-cluster chart rather than etcd-operator, given the etcd instance is whats truly required.
This allows the upgrade/removal of voltha to take its etcd-cluster with it, without removing etcd-operator.

Update the voltha chart to make the inclusion of freeradius optional and remove unused consul config references.

Tested by running:
helm install -n cord-kafka incubator/kafka --set persistence.enabled=false --set zookeeper.persistence.enabled=false
helm install -n etcd-operator stable/etcd-operator

  wait for etcdclusters CRD to be created...

helm dep update ~/source/helm-charts/voltha
helm install -n voltha ~/source/helm-charts/voltha

Change-Id: I7001943d74fdbd38f4d786982c70908ba24fd0ca
diff --git a/voltha/values.yaml b/voltha/values.yaml
index 81fe079..6237196 100644
--- a/voltha/values.yaml
+++ b/voltha/values.yaml
@@ -45,18 +45,14 @@
           targetPort: 50555
 
 etcd:
-  operator:
+  cluster:
     enabled: true
 
-etcd-operator:
-  customResources:
-    createEtcdClusterCRD: true
+freeradius:
+  enabled: true
 
 kafkaReleaseName: cord-kafka
-etcdReleaseName: voltha-etcd
-
-consul:
-  enabled: false
+etcdReleaseName: etcd-cluster
 
 images:
   vcore: