hokey lint should look at revocation packets and warn if they use a weak digest algorithm like SHA1

subkey 0x61092ABB97419DF3 in the attached OpenPGP certificate appears to have been revoked by the primary key -- but the subkey revocation signature packet uses SHA-1.

A system that is unwilling to accept SHA-1 signatures might consider the subkey "unrevoked", since the subkey binding signature uses SHA-256.

hokey lint should warn when any subkey revocation signature packet uses a known-weak digest algorithm.

it should probably do the same for any type of revocation signature packet it encounters.