remove two unused metrics

Author: Han Kang

pkg/master/BUILD

@@ -129,7 +129,6 @@ go_library(
         "//staging/src/k8s.io/client-go/kubernetes/typed/core/v1:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes/typed/discovery/v1beta1:go_default_library",
         "//staging/src/k8s.io/client-go/rest:go_default_library",
-        "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",
         "//vendor/k8s.io/utils/integer:go_default_library",
         "//vendor/k8s.io/utils/net:go_default_library",

pkg/master/master.go

@@ -89,7 +89,6 @@ import (
 	"k8s.io/kubernetes/pkg/serviceaccount"
 	nodeutil "k8s.io/kubernetes/pkg/util/node"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"k8s.io/klog"
 
 	// RESTStorage installers