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/authorization/authorizer/interfaces.go

@@ -56,7 +56,7 @@ type Attributes interface {
 	GetAPIVersion() string
 
 	// IsResourceRequest returns true for requests to API resources, like /api/v1/nodes,
-	// and false for non-resource endpoints like /api, /healthz, and /swaggerapi
+	// and false for non-resource endpoints like /api, /healthz
 	IsResourceRequest() bool
 
 	// GetPath returns the path of the request

vendor/k8s.io/apiserver/pkg/authorization/authorizerfactory/OWNERS

@@ -1,3 +1,5 @@
+# See the OWNERS docs at https://go.k8s.io/owners
+
 reviewers:
 - deads2k
 - dims

vendor/k8s.io/apiserver/pkg/authorization/path/doc.go

@@ -15,4 +15,4 @@ limitations under the License.
 */
 
 // Package path contains an authorizer that allows certain paths and path prefixes.
-package path
+package path // import "k8s.io/apiserver/pkg/authorization/path"