[PATCH 3 of 3 STABLE] formatting: drop `grey`, our custom black version

[Augie Fackler]

On Tue, Oct 29, 2019 at 12:08:58PM +0100, Pierre-Yves David wrote:
> # HG changeset patch
> # User Pierre-Yves David <pierre-yves.david at octobus.net>
> # Date 1572343645 -3600
> #      Tue Oct 29 11:07:25 2019 +0100
> # Branch stable
> # Node ID 17c367aaedbc1f72e6d5b19fb1de8828a1dca3ab
> # Parent  0e9acc6539a0d23b2a7428ad86cc4fa79e47d7a5
> # EXP-Topic switch-to-black
> # Available At https://bitbucket.org/octobus/mercurial-devel/
> #              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 17c367aaedbc
> formatting: drop `grey`, our custom black version

queued, thanks

I'll send some follow-ups to try and prevent some footguns, I think.