Fail tests when no facts are found in facterdb

[serialh0bbyist]

I think we should have the following line raise an error vs. the default of warning. Warnings usually do not stop pipelines. This gives users a false sense of their code being tested on every OS and Version defined in the metadata.json for the puppet module.

https://github.com/voxpupuli/rspec-puppet-facts/blob/master/lib/rspec-puppet-facts.rb#L145