NOTE: This contains a breaking change to the secp256k1.GenPrivKeySecp256k1 function that we neglected to document in the changelog. The derivation here has changed to guarantee that it returns a valid key, which means it will return a different private key than in previous versions for the same secret.
https://github.com/tendermint/tendermint/blob/v0.31.3/CHANGELOG.md#v0313