[Twisted-Python] overview: new review queue venue

[Werner Thie]

Thank you all for that great and massive move!

Me running twisted almost exclusively on FreeBSD, what is the reason for

 > We could also potentially just replace our buildbot build farm with a
 > combination of appveyor and travis-ci; this would remove FreeBSD from
 > our list of supported platforms, ...

Thanks for enlightening me.

Werner