在GoLang中执行反向代理时确认TLS证书

In GoLang I'm using NewSingleHostReverseProxy to preform a reverse proxy, however I need to confirm the SSL certificates of the host site, to make sure I have the correct secure certificate... any ideas how I should do this? Should I be doing this with the handler or transport? I'm new to GoLang and still getting my head around it. Thanks

proxy := httputil.NewSingleHostReverseProxy(&url.URL{
         Scheme: "https",
         Host:   "sha256.badssl.com",
})

http.ListenAndServe("127.0.0.1:80", proxy)