Compatibility with octez 11.0rc1
Octez 11.0rc1 changes a bit the interface of Error_monad (see tezos/tezos!3506 (merged)). Moreover the baking lib for Florence is no longer built, this version uses the one from Granada.
This version has been compiled with tezos/tezos:v11.0-rc1
at commit 36055190bb
(I've also updated the Makefile)