Spec for .on_supported_os with no operatingsystemmajrelease
Spec for .on_supported_os with no operatingsystemmajrelease

Adds a test to cover a previously untested conditional in
`on_supported_os` where the major release number is determined by
splitting the `operatingsystemrelease` value when the fact set does not
contain a `operatingsystemmajrelease` fact.

mcanevet/rspec-puppet-facts,DavidS/rspec-puppet-facts