Support `QuickCheck` version `2.18.0.0` (`aeson`).

[jonathanknowles]

Version 2.18.0.0 of the QuickCheck package has been released, but the most recent revision of aeson on Hackage (2.2.3.0-r4) has an effective upper bound of < 2.17:

    , QuickCheck            ^>=2.14.3   || ^>=2.15    || ^>=2.16.0.0

See also:

• Support QuickCheck version 2.17.1.0 (aeson). #1147

[ivanperez-keera]

Just run into this.