add vendor & update README.md

vendor/github.com/gin-gonic/autotls/autotls.go

@@ -0,0 +1,26 @@
+package autotls
+
+import (
+	"crypto/tls"
+	"net/http"
+
+	"golang.org/x/crypto/acme/autocert"
+)
+
+// Run support 1-line LetsEncrypt HTTPS servers
+func Run(r http.Handler, domain ...string) error {
+	return http.Serve(autocert.NewListener(domain...), r)
+}
+
+// RunWithManager support custom autocert manager
+func RunWithManager(r http.Handler, m *autocert.Manager) error {
+	s := &http.Server{
+		Addr:      ":https",
+		TLSConfig: &tls.Config{GetCertificate: m.GetCertificate},
+		Handler:   r,
+	}
+
+	go http.ListenAndServe(":http", m.HTTPHandler(nil))
+
+	return s.ListenAndServeTLS("", "")
+}