Python 3.6 wheels uploaded - need testing

Hi,

I just uploaded pypi wheels for Python 3.6 on OSX and Linux; I think
we're going to be uploading Windows wheels soon as well.

We have an odd test error for the Python 3.6 wheels on OSX :
https://github.com/matplotlib/matplotlib/issues/7799 . We're guessing
that this error will be uncommon in practice, but we'd love feedback
on your experience of using these wheels:

pip install --user -U matplotlib

Cheers,

Matthew