Update module k8s.io/client-go to v0.19.0 (#369)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

go.mod

@@ -14,13 +14,13 @@ require (
 	github.com/pquerna/cachecontrol v0.0.0-20180517163645-1555304b9b35 // indirect
 	github.com/spf13/cobra v1.0.0
 	github.com/spf13/pflag v1.0.5
-	golang.org/x/crypto v0.0.0-20200220183623-bac4c82f6975
+	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9
 	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
 	golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208
 	golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543
 	gopkg.in/square/go-jose.v2 v2.3.1 // indirect
 	gopkg.in/yaml.v2 v2.3.0
-	k8s.io/apimachinery v0.18.8
-	k8s.io/client-go v0.18.8
+	k8s.io/apimachinery v0.19.0
+	k8s.io/client-go v0.19.0
 	k8s.io/klog v1.0.0
 )