Ridley has the same dependency, it's just here for completeness.

This pull request is to remove the explicit requirement to make things more lax with the dependent libraries that we're including in. If a user has OJ on their machine and one of the dependent libraries no longer explicitly requires a JSON gem, then the user will be using OJ.

as a side note: Ridley requires JSON because it supports CRuby and JRuby. Ridley needs to maintain it's JRuby support for an upcoming project from RiotGames.