This is available as closed alpha, but we working hard on extending this functionality to be actually usable (read: scenarios, because you usually need to do at least some sort of "setUp").

If you are interested in this, please subscribe to http://support.apiary.io/forums/120125-general/suggestions/3... and we'll let you know once it will be available for testing.

It's now one of our three running projects and you're gonna love it ;)