Update vendor

vendor/github.com/rancher-sandbox/gofilecache/gofilecache.go

@@ -0,0 +1,34 @@
+// Copyright 2017 The Go Authors, SUSE LLC. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gofilecache
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+)
+
+const cacheREADME = `This directory holds a cache directory tree.
+This has been created using github.com/rancher-sandbox/gofilecache/
+`
+
+func InitCache(cacheDir string) *Cache {
+	if err := os.MkdirAll(cacheDir, 0777); err != nil {
+		log.Fatalf("failed to initialize build cache at %s: %s\n", cacheDir, err)
+	}
+	if _, err := os.Stat(filepath.Join(cacheDir, "README")); err != nil {
+		// Best effort.
+		ioutil.WriteFile(filepath.Join(cacheDir, "README"), []byte(cacheREADME), 0666)
+	}
+
+	c, err := Open(cacheDir)
+	if err != nil {
+		log.Fatalf("failed to initialize build cache at %s: %s\n", cacheDir, err)
+	}
+	return c
+}
+
+var ()