Licensing needs rework

[SnarkBoojum]

README.md says to have a look at the LICENSE and COPYING files. The first is LGPL-3+ and the second is GPL-3.

There's also a COPYING.LESSER which is LGPL-3. The opam file also says LGPL-3+.

Oh, and the homepage says LGPL-3.

That makes three different licenses... could you clarify the situation?

I would like to package coq-relation-algebra for Debian, but my package won't fly if there's a licensing conendrum.