[PATCH] Set up Alembic for database migrations

[Frédéric Mangano-Tarumi]

Lukas Fleischer [2020-02-26 14:00:51 +0100]
> We should also think about phasing out the text files in the upgrading/
> subdirectory. Maybe we should simply keep them for one or two releases
> and remove the directory entirely later? If anybody ever still needs
> them after they have been removed, they can still be recovered from the
> Git history...

I don’t know who reads the upgrading instructions, but how about having
a 4.x.0-and-later.txt saying that SQL migrations are now handled by
Alembic, and referring to migrations/README?

Let’s also keep in mind that some upgrades might require manual
intervention anyway. In my opinion these breaking changes should be
documented in commit messages and synthesized in release notes, but
whatever the AUR team is used to should be fine too.