Add scheme to server address (#1734)

This makes it easier to CMD + click the URL when the server is started.

server.go

@@ -19,7 +19,7 @@ import (
 // interrupt and kill signals and will attempt to stop the application
 // gracefully. This will also start the Worker process, unless WorkerOff is enabled.
 func (a *App) Serve(srvs ...servers.Server) error {
-	a.Logger.Infof("Starting application at %s", a.Options.Addr)
+	a.Logger.Infof("Starting application at http://%s", a.Options.Addr)
 
 	payload := events.Payload{
 		"app": a,