Nikola Dipanov

I think this is expected behavior. If you do declare `z` as an `attr`, it will get copied (as you noticed). Pickling implementation (`__setstate__` that is) only looks at those....

Another option is, of course, to provide your own implementation of set/getstate, which attrs will honor, but is arguably clunky/inelegant.

Hmmm... the CI failures do not seem to be related to my change.

Closed and re-oppened in order to re-kick travis