update vendor

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

vendor/github.com/prometheus/client_golang/examples/simple/main.go

@@ -0,0 +1,31 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// A minimal example of how to include Prometheus instrumentation.
+package main
+
+import (
+	"flag"
+	"log"
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
+
+func main() {
+	flag.Parse()
+	http.Handle("/metrics", promhttp.Handler())
+	log.Fatal(http.ListenAndServe(*addr, nil))
+}