@bsipocz - long delay, but now had a look: these changes certainly seem fine, and as it would be good to get python3 builds working properly, I'm all in favour. I'm not really set up well to test them, though...

@mhvk - I'm not sure about the best way for the test, there isn't much docs here to do it within the helpers. Maybe the simplest is to update the helpers within astropy/astropy#4481 once this is merged and iron out any problems that come up before it goes into a release.

Also should this have a changelog entry? If yes, which milestone?

@bsipocz - yes, sounds good to merge and test in astropy. Would this be for astropy/astropy#4556? As said, it looks good to me, but feel sufficiently unsure that I'd rather have @astrofrog or @eteq have a look.

@bsipocz - definitely changelog it. Re: milestone I think this (and the corresponding sphinx builds) should go in 1.2 - generally we've considered "doc changes" to be ok for bugfix branches, but I think this is signficant enough that it's better done in a new major release.

@eteq - OK. I agree that this is more than a docs change, but maybe we want to provide py3 docs build support for the affiliates before 1.2?

Changelog added.

Hmm, this is an interesting question that perhaps @astrofrog or @embray want to weigh on on: do we want to consider doing a helper 1.2 release before the core package? We can always do 1.2.1 (or later) before the core package 1.2 release...

@eteq - Rebased, but left the changelog in 1.2. I can move it you decide to include this in 1.1.3 :)

@bsipocz - as per discussion on gitter, looks like this is suitable for 1.1.3, so you can move it to that part of the changelog and then we'll merge.

(I'm pretty sure the one travis failure is a red herring, and the appveyor issue is the continuing "Chocolatey" business that seems to be some network issue?)

@eteq - Done.

Alright, great. Merging!