Don't exit abruptly if there aren't yet any minions right after

the cluster is created.

cluster/validate-cluster.sh

@@ -31,7 +31,7 @@ trap 'rm -rf "${MINIONS_FILE}"' EXIT
 attempt=0
 while true; do
   "${KUBE_ROOT}/cluster/kubectl.sh" get nodes -o template -t $'{{range.items}}{{.metadata.name}}\n{{end}}' --api-version=v1beta3 > "${MINIONS_FILE}"
-  found=$(grep -c . "${MINIONS_FILE}")
+  found=$(grep -c . "${MINIONS_FILE}") || true
   if [[ ${found} == "${NUM_MINIONS}" ]]; then
     break
   else