[Toaster] [RFC] - What's a build artifact?

[Barros Pena, Belen]

Our first go at Toaster was very much thinking of a local use case. From
1.7 we'll start focusing on the remote use case (this is a web application
after all, right?).

One of the things we need to add is the ability to download build
artifacts that have been produced (and are stored) on a remote build
server. This brings up the question: what is a build artifact? I mean:
what do you want to be able to download after a build?

Is it just rootfs files? Or is it also:

* cooker log
* task logs
* [your suggestion here]

Thanks!

Belén