Cleanppo hyperopt not working - not hyperopt available.

Annika is working on her MoonLander env, and we have created a hyperopt script for cleanppo. I realized that we do not have any hyperopt for cleanppo in devel. The call is failing with the following error:

joblib.externals.loky.process_executor.BrokenProcessPool: A result has failed to un-serialize. Please ensure that the objects returned by the function are always picklable.

Steps to reproduce: