Python 3.9 available on Travis

[jugmac00]

Finally...

https://travis-ci.community/t/python-3-9-0-build/10091

[icemac]

Thank you for this info. We do not have the infrastructure to automatically switch from 3.9-dev to 3.9 so we have to do it manually when encountering a dev version.

I am going to close this issue as I see no actionable items here.
Feel free to reopen if you disagree.

[jugmac00]

At first - yes, this was only informational, but when you said we have no infrastructure for mass changes, I remembered that I evaluated all-repos by @asottile a year ago, but could not wrap my head around the autofixer process, so I had another look today... and what the f... looks like I am creating tons of PRs currently, automatically!

e.g. zopefoundation/zope.sqlalchemy#50

I will try to find some time to write a blog post.

[jugmac00]

I wrote a concise today-I-learned on how to update all Zope repos with a single command:
https:/jugmac00/til/blob/master/zope/how-to-update-all-zopefoundation-repositories-at-once.md

[mgedmin]

@jugmac00 that link would fit well in #1.