Bump k8s.io/client-go from 0.17.0 to 0.20.0 in /cmd/gtoken-webhook

cmd/gtoken-webhook/go.mod

@@ -3,17 +3,15 @@ module github.com/doitintl/gtoken-webhook
 go 1.13
 
 require (
-	github.com/google/go-cmp v0.3.1
+	github.com/google/go-cmp v0.5.2
 	github.com/prometheus/client_golang v1.3.0
 	github.com/sirupsen/logrus v1.4.2
 	github.com/slok/kubewebhook v0.3.0
 	github.com/urfave/cli v1.22.2
-	golang.org/x/oauth2 v0.0.0-20191202225959-858c2ad4c8b6 // indirect
-	golang.org/x/time v0.0.0-20191024005414-555d28b269f0 // indirect
-	k8s.io/api v0.17.0
-	k8s.io/apimachinery v0.17.0
-	k8s.io/client-go v0.17.0
-	k8s.io/utils v0.0.0-20191218082557-f07c713de883 // indirect
+	k8s.io/api v0.20.0
+	k8s.io/apimachinery v0.20.0
+	k8s.io/client-go v0.20.0
+	k8s.io/klog v1.0.0 // indirect
 	sigs.k8s.io/controller-runtime v0.4.0
 )