Prevent the installation of the 7.* ohai gem as 7.0.0-rc is installed now by default and breaks (at least in RHEL) omnibus.
using ~> 6.12 instead of < 7.0.0
added the leading zero for form
Removed leading zero in Ohai dep.
Merge pull request #93 from nmilford/master

Prevent the installation of the 7.* ohai gem