Updated vendor for changes to container-diff

vendor/github.com/GoogleContainerTools/container-diff/cmd/util/output/output.go

@@ -0,0 +1,37 @@
+/*
+Copyright 2018 Google, Inc. All rights reserved.
+
+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.
+*/
+
+package output
+
+import (
+	"fmt"
+	"github.com/spf13/cobra"
+	"os"
+)
+
+var quiet bool
+
+// PrintToStdErr prints to stderr if quiet flag isn't enabled
+func PrintToStdErr(output string, vars ...interface{}) {
+	if !quiet {
+		fmt.Fprintf(os.Stderr, output, vars...)
+	}
+}
+
+// AddFlags adds quiet flag to suppress output to stderr
+func AddFlags(cmd *cobra.Command) {
+	cmd.Flags().BoolVarP(&quiet, "quiet", "q", false, "Suppress output to stderr.")
+}