Release 22.2.0?

[sfgeorge]

#146 Announced a version 22.2.0 to the README history, however no such release exists.

Assuming it's stable, we should release 22.2.0. Otherwise, we should change the wording on the README, e.g. 22.2.0 to "In Development"

[Tinche]

That's just the next version number, if there's no release date it hasn't been released.

I've released it now though, under 23.1.0.