Mainly a note to our future selves, but we need to ensure we output a SemVer compliant version string (vs a RubyGems version string). This mainly affects pre-release versions...think `1.0.0.rc.1` vs `1.0.0-rc.1`. We can leverage mixlib-versioning for this sort of conversion.

Something we can solve when we do the work mentioned in https://github.com/opscode/omnibus-ruby/issues/134.