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/generic/options.go

@@ -47,6 +47,6 @@ type RESTOptionsGetter interface {
 // StoreOptions is set of configuration options used to complete generic registries.
 type StoreOptions struct {
 	RESTOptions RESTOptionsGetter
-	TriggerFunc storage.TriggerPublisherFunc
+	TriggerFunc storage.IndexerFuncs
 	AttrFunc    storage.AttrFunc
 }