use kubefed v1.6.2

v1.7.x kubefed only works with RBAC enabled clusters

Change-Id: I76c8c582066af7abb6923dd0174650f84cbb9c8a
diff --git a/metadata/service/master/cluster.yml b/metadata/service/master/cluster.yml
index 50e5ce6..50e6d81 100644
--- a/metadata/service/master/cluster.yml
+++ b/metadata/service/master/cluster.yml
@@ -64,7 +64,7 @@
         enabled: False
         name: federation
         namespace: federation-system
-        source: https://dl.k8s.io/v1.7.3/kubernetes-client-linux-amd64.tar.gz
-        hash: 8d66c7912914ac9add514e660fdc8c963b748a7c588c43a14533157a9f0e1c92
+        source: https://dl.k8s.io/v1.6.2/kubernetes-client-linux-amd64.tar.gz
+        hash: f8ef17b8b4bb8f6974fa2b3faa992af3c39ad318c30bdfe1efab957361d8bdfe
         service_type: NodePort
         dns_provider: coredns