tmp not in /tmp? are you kidding me?
remove tmp after exceptions, fix security issue

what is even happen here
er, one tmp per install run. yeah.
oh ffs why was that there
per-gem tmp, copy EVERYTHING rubygems installed
that was duplicated
move ConfigMap into RubygemsIntegration
use named tmp for path gems too
pull out repository subdirectories for RG compat
install to new dir inside root-owned dir
make the sudo test env more obvious
only copy files that exist
Add Rubygems metadata to RSpec
handle extensions from Rubygems 2.2, with test

fixes #2847
slightly less deep