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/requirements.yaml b/voltha/requirements.yaml
index b4f3bdc..241c094 100644
--- a/voltha/requirements.yaml
+++ b/voltha/requirements.yaml
@@ -14,11 +14,7 @@
 # limitations under the License.
 
 dependencies:
-- name: etcd-operator
-  version: 0.7.7
-  repository: https://kubernetes-charts.storage.googleapis.com/
-  condition: etcd.operator.enabled
-- name: consul
-  version: 1.3.5
-  repository: https://kubernetes-charts.storage.googleapis.com/
-  condition: consul.enabled
+- name: etcd-cluster
+  version: 0.1.1
+  repository: file://../etcd-cluster
+  condition: etcd.cluster.enabled