Move auth import into main programs so libraries don't inherit it by default

cmd/kubectl/main.go

@@ -8,6 +8,10 @@ import (
 
 	"sigs.k8s.io/kustomize/cmd/kubectl/kubectlcobra"
 	"sigs.k8s.io/kustomize/kyaml/commandutil"
+
+	// This is here rather than in the libraries because of
+	// https://github.com/kubernetes-sigs/kustomize/issues/2060
+	_ "k8s.io/client-go/plugin/pkg/client/auth"
 )
 
 func main() {