parallel: Ensure we have some crucial subdirectories of /var
parallel: Ensure we have some crucial subdirectories of /var

Also move sysroot creation up a step - each commit is kind of
expensive at present.

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