Fix run_fact acceptance test helper
Fix run_fact acceptance test helper

As of
https://github.com/puppetlabs/puppet_litmus/commit/96f562447eed027aca7575b252e7fe6c30bf13f9
Litmus returns the first result object from the run_shell() method, so
don't attempt to extract it ourselves.

natemccurdy/yumrepos_fact