Adding workaround to the sphinx builds - #5568

@astrofrog - thanks for merging this! However, I noticed the following issue with this pull request:

• The milestone has not been set

Would it be possible to fix this? Thanks!

This is an experimental bot being written by @astrofrog - let me know if the message above is incorrect!

@bsipocz Is this related to this failure in ccdproc?

@MSeifert04 - Yes, this is a failure everywhere that uses astropy-helpers <1.3 and Sphinx >=1.5. I'm about to open a fix for the helpers now. You can always set the SPHINX_VERSION='<1.5' to the travis file, just like in this PR.

@astrofrog @eteq - Since the astropy-helpers 1.3 is imminent I think it makes sense to do the fix there, or would you prefer to add back a version limitation to ci-helpers?

ok, thanks. I was wondering what happened there.

@bsipocz - we won't necessarily do a final helpers release for another week, so I think its probably best to back up ci-helpers until then, as otherwise affiliated packages will be seeing errors for a whole week...

Fair enough, I'm revering it then. Looking at the travis backlog it would take a few hours to get the green lights.