Ohai 8.13 released

This is just a release to rubygems, and is pretty minor, so most people won’t be affected either way. There is no corresponding public Chef or ChefDK release binary, and won’t be until Chef 12.9. Changelog here: https://github.com/chef/ohai/blob/master/CHANGELOG.md#8130-2016-03-24

–John Keiser, Chef