We have to be careful about avoiding outer loop loop_var conflicts in
ansible. Because the zuul-jobs roles are meant to be reconsumed
elsewhere we should not use 'item' loopvars and instead set them to
something a bit more unique.
We use a zj_ prefix to try and be unique to this repo and document this
convention.
Change-Id: I20b9327a914890e9eafcb2b36dc8c23fb472bc8f
4ed66807a0