sss/codensity: Typeable instance for Codensity
sss/codensity: version bump

bumping version from current hackage version, which seems to be on
version 4.1.0.1 as per
<https://hackage.haskell.org/package/kan-extensions>.
sss/codensity: version bump

as per the second bullet point in section 2 in
<https://www.haskell.org/haskellwiki/Package_versioning_policy> addition
of instances warrants a bump in the minor version number.