Update vendor

vendor/github.com/google/go-containerregistry/pkg/authn/basic.go

@@ -0,0 +1,29 @@
+// 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 authn
+
+// Basic implements Authenticator for basic authentication.
+type Basic struct {
+	Username string
+	Password string
+}
+
+// Authorization implements Authenticator.
+func (b *Basic) Authorization() (*AuthConfig, error) {
+	return &AuthConfig{
+		Username: b.Username,
+		Password: b.Password,
+	}, nil
+}