Got drush-deploy working with Ariadne and skeletor like so:
Added gem to Gemfile and re-installed (and rehashed rbenv)
Added Capfile below to ariadne root
Skeletor was clones elsewhere
drush alias was placed in ~/.drush
These commands were run:
cap TARGET=skeletor.vagrant deploy:setup
REPO=~/repos/drupal-skeletor MAKEFILE=build-skeletor.make cap TARGET=skeletor.vagrant deploy