Vendor in c/image with sigstore support

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

vendor/github.com/google/go-containerregistry/pkg/name/errors.go

@@ -0,0 +1,42 @@
+// Copyright 2018 Google LLC 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 name
+
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrBadName is an error for when a bad docker name is supplied.
+type ErrBadName struct {
+	info string
+}
+
+func (e *ErrBadName) Error() string {
+	return e.info
+}
+
+// newErrBadName returns a ErrBadName which returns the given formatted string from Error().
+func newErrBadName(fmtStr string, args ...interface{}) *ErrBadName {
+	return &ErrBadName{fmt.Sprintf(fmtStr, args...)}
+}
+
+// IsErrBadName returns true if the given error is an ErrBadName.
+//
+// Deprecated: Use errors.Is.
+func IsErrBadName(err error) bool {
+	var berr *ErrBadName
+	return errors.As(err, &berr)
+}