use istio client-go library instead of knative (#1661)

use istio client-go library instead of knative
bump kubernetes dependency version
change code coverage to codecov

vendor/sigs.k8s.io/controller-tools/pkg/schemapatcher/internal/yaml/convert.go

@@ -0,0 +1,61 @@
+/*
+Copyright 2019 The Kubernetes 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.
+*/
+
+package yaml
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"gopkg.in/yaml.v3"
+)
+
+// ToYAML converts some object that serializes to JSON into a YAML node tree.
+// It's useful since it pays attention to JSON tags, unlike yaml.Unmarshal or
+// yaml.Node.Decode.
+func ToYAML(rawObj interface{}) (*yaml.Node, error) {
+	if rawObj == nil {
+		return &yaml.Node{Kind: yaml.ScalarNode, Value: "null", Tag: "!!null"}, nil
+	}
+
+	rawJSON, err := json.Marshal(rawObj)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal object: %v", err)
+	}
+
+	var out yaml.Node
+	if err := yaml.Unmarshal(rawJSON, &out); err != nil {
+		return nil, fmt.Errorf("unable to unmarshal marshalled object: %v", err)
+	}
+	return &out, nil
+}
+
+// changeAll calls the given callback for all nodes in
+// the given YAML node tree.
+func changeAll(root *yaml.Node, cb func(*yaml.Node)) {
+	cb(root)
+	for _, child := range root.Content {
+		changeAll(child, cb)
+	}
+}
+
+// SetStyle sets the style for all nodes in the given
+// node tree to the given style.
+func SetStyle(root *yaml.Node, style yaml.Style) {
+	changeAll(root, func(node *yaml.Node) {
+		node.Style = style
+	})
+}