Implement replicaLoadBalancer boolean flag. (#38)

The flag adds a replica service with the name cluster_name-repl and
a DNS name that defaults to {cluster}-repl.{team}.{hostedzone}.

The implementation converted Service field of the cluster into a map
with one or two elements and deals with the cases when the new flag
is changed on a running cluster
(the update and the sync should create or delete the replica service).
In order to pick up master and replica service and master endpoint
when listing cluster resources.

* Update the spec when updating the cluster.

pkg/util/constants/kubernetes.go

@@ -2,6 +2,7 @@ package constants
 
 import "time"
 
+// General kubernetes-related constants
 const (
 	ListClustersURITemplate     = "/apis/" + TPRVendor + "/" + TPRApiVersion + "/namespaces/%s/" + ResourceName       // Namespace
 	WatchClustersURITemplate    = "/apis/" + TPRVendor + "/" + TPRApiVersion + "/watch/namespaces/%s/" + ResourceName // Namespace