Rewrite for testability

Testing the methods inside of the function is a complete pain.  This
moves the code out to use the PuppetX pattern and adds some basic unit
tests that validate the logic.

Rakefile

@@ -35,7 +35,7 @@ PuppetSyntax.exclude_paths = exclude_paths
 
 desc "Run acceptance tests"
 RSpec::Core::RakeTask.new(:acceptance) do |t|
-  t.pattern = 'spec/acceptance'
+  t.pattern = 'spec/**/*.rb'
 end
 
 desc "Populate CONTRIBUTORS file"