copilot: please support optparse-applicative-0.19

[juhp]

I think it is good to try to keep copilot in Stackage Nightly,
this guarantees it will land in the next Stackage LTS major version.

Is it possible to revise the current 4.5.1 release to allow optparse-applicative-0.19?
Or at least for 4.5.2 perhaps?