[Pharo-dev] Book farm working again

Hi https://ci.inria.fr/pharo-contribution/view/Books/ I realised that jenkins dropped the connection to the github repositories of the books and that they were not updated. You can find my current evening occupation: Learning OOP with Pharo :) I fixed some problems in UnifiedFFI and clean a bit before restarting to work on Pillar. And we get more green books job. Stef