DEP: Bump Cython to 0.29.13

[TomAugspurger]

In preperation for Python 3.8, we need to ensure we compile the sdist
with new enough versions of Cython. This is the latest current release.

xref #28341

[TomAugspurger]

Just the SSL doc build issue causing the failure.

[jbrockmendel]

LGTM. is the SSL thing something we can suppress for a day?

[TomAugspurger]

By "suppress" do you mean ignore, or a configuration change? I'm happy to just ignore for a day or two to see if things resolve themselves.

…

On Wed, Sep 11, 2019 at 5:07 PM jbrockmendel ***@***.***> wrote: LGTM. is the SSL thing something we can suppress for a day? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#28391?email_source=notifications&email_token=AAKAOIX2IWHHT5TZGZE3PCLQJFT3HA5CNFSM4IVX2KYKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6QBNTY#issuecomment-530585295>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAKAOIXYIBPCTQ25COHDB2TQJFT3HANCNFSM4IVX2KYA> .

[jreback]

thanks @TomAugspurger

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

$ git checkout 0.25.x
$ git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

$ git cherry-pick -m1 b3bd4dfc855732c81de1019090fe4bc9b7354788

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

$ git commit -am 'Backport PR #28391: DEP: Bump Cython to 0.29.13'

4. Push to a named branch :

git push YOURFORK 0.25.x:auto-backport-of-pr-28391-on-0.25.x

5. Create a PR against branch 0.25.x, I would have named this PR:

"Backport PR #28391 on branch 0.25.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to suggest an improvement.

[TomAugspurger]

I'll do the backport.