HTTP signatures libraray

You might want to update it for draft 12. There are a few projects using those changes now. And the entire ball of wax will need to be tossed out eventually, because draft-davage has been superceded, but the fediverse hasn’t done that yet.

The caveats with draft 12 is that very few projects support it fully, so you’ll probably want to accept hs2019 (or whatever they called the new dummy algorithm) but still generate rsa algorithms. Once more projects support hs2019 we can start sending it. I doubt that will happen though because it is a dead draft. Nobody seems to like the replacement - I sure don’t. So we’ll probably be stuck with draft-cavage at version 12 for a long while.