Apitests

Apologies for not merging it last week,
but I messed up my last rebase beyond all repair.

Lots of goodies (you can generate records in bulk, adding support for kattelo api, e.t.c)

Slowly working my way up to activation_keys, hopefully I will finish them, after foreman installer starts working again :)

This shouldn't require such an extensive review as last time, because it is mostly just a manual rebase :-)