tests: Actually test pack functionality
tests: Actually test pack functionality

With --keep-loose we were just using the loose objects.

resin-io/ostree,GNOME/ostree,sujitfulse/ostree,leandrosansilva/ostree,sujitfulse/ostree,resin-io/ostree,GNOME/ostree,gatispaeglis/ostree,leandrosansilva/ostree,resin-io/ostree,GNOME/ostree,GNOME/ostree,gatispaeglis/ostree,sujitfulse/ostree,resin-io/ostree,gatispaeglis/ostree,leandrosansilva/ostree,leandrosansilva/ostree,GNOME/ostree,sujitfulse/ostree,gatispaeglis/ostree,gatispaeglis/ostree,leandrosansilva/ostree,resin-io/ostree,sujitfulse/ostree,gatispaeglis/ostree