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/k8s.io/apiserver/pkg/registry/rest/create_update.go

@@ -0,0 +1,52 @@
+/*
+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 rest
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+)
+
+// RESTCreateUpdateStrategy is a union of RESTUpdateStrategy and RESTCreateStrategy,
+// and it defines the minimum validation, accepted input, and name generation
+// behavior to create and update an object that follows Kubernetes API conventions.
+type RESTCreateUpdateStrategy interface {
+	RESTCreateStrategy
+	// AllowCreateOnUpdate returns true if the object can be created by a PUT.
+	AllowCreateOnUpdate() bool
+	// PrepareForUpdate is invoked on update before validation to normalize
+	// the object.  For example: remove fields that are not to be persisted,
+	// sort order-insensitive list fields, etc.  This should not remove fields
+	// whose presence would be considered a validation error.
+	PrepareForUpdate(ctx context.Context, obj, old runtime.Object)
+	// ValidateUpdate is invoked after default fields in the object have been
+	// filled in before the object is persisted.  This method should not mutate
+	// the object.
+	ValidateUpdate(ctx context.Context, obj, old runtime.Object) field.ErrorList
+	// AllowUnconditionalUpdate returns true if the object can be updated
+	// unconditionally (irrespective of the latest resource version), when
+	// there is no resource version specified in the object.
+	AllowUnconditionalUpdate() bool
+}
+
+// Ensure that RESTCreateUpdateStrategy extends RESTCreateStrategy
+var _ RESTCreateStrategy = (RESTCreateUpdateStrategy)(nil)
+
+// Ensure that RESTCreateUpdateStrategy extends RESTUpdateStrategy
+var _ RESTUpdateStrategy = (RESTCreateUpdateStrategy)(nil)