clean up temp dir in unit test
clean up temp dir in unit test

warmchang/minikube,kubernetes/minikube,dalehamel/minikube,warmchang/minikube,kubernetes/minikube,kubernetes/minikube,dalehamel/minikube,kubernetes/minikube,warmchang/minikube,warmchang/minikube,dalehamel/minikube,warmchang/minikube,warmchang/minikube,warmchang/minikube,kubernetes/minikube,kubernetes/minikube,kubernetes/minikube