Finish the most recent Consensus release to CHaP

[nfrisby]

#292 update the ledger. And #301 created the corresponding release commit.

However, https://github.com/input-output-hk/cardano-haskell-packages/pull/443 is failing due to some Nix/cabal infelicities. We can't finish the release until we fixup the CHaP build, and the path forward is unfortunately not obvious. (See https://github.com/input-output-hk/cardano-haskell-packages/pull/445 vs https://github.com/input-output-hk/cardano-haskell-packages/pull/446 eg.)

[nfrisby]

We anticipate that the obstacle was resolved by #304 and #308.

If so, https://github.com/input-output-hk/cardano-haskell-packages/pull/443 will be merged as is.