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/client-go/discovery/fake/discovery.go

@@ -53,13 +53,29 @@ func (c *FakeDiscovery) ServerResourcesForGroupVersion(groupVersion string) (*me
 }
 
 // ServerResources returns the supported resources for all groups and versions.
+// Deprecated: use ServerGroupsAndResources instead.
 func (c *FakeDiscovery) ServerResources() ([]*metav1.APIResourceList, error) {
+	_, rs, err := c.ServerGroupsAndResources()
+	return rs, err
+}
+
+// ServerGroupsAndResources returns the supported groups and resources for all groups and versions.
+func (c *FakeDiscovery) ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+	sgs, err := c.ServerGroups()
+	if err != nil {
+		return nil, nil, err
+	}
+	resultGroups := []*metav1.APIGroup{}
+	for i := range sgs.Groups {
+		resultGroups = append(resultGroups, &sgs.Groups[i])
+	}
+
 	action := testing.ActionImpl{
 		Verb:     "get",
 		Resource: schema.GroupVersionResource{Resource: "resource"},
 	}
 	c.Invokes(action, nil)
-	return c.Resources, nil
+	return resultGroups, c.Resources, nil
 }
 
 // ServerPreferredResources returns the supported resources with the version