Prior to this commit, the test module used in testing was using
a Modulefile rather than metadata.json. Switch to metadata.json
instead since Modulefile is deprecated and was causing a deprecation
warning during acceptance testing.
Add tests to ensure that the face (puppet yardoc) works from end to
end. In other words, ensure that when given a module, puppet yardoc can
successfully evaluate the .pp and .rb files present in the module and
produce the expected HTML.
Add tests for the remaining two Puppet-specific handlers that were
not tested in the previous commit. Specifically, add tests for the
3.x function handler and the host class handler.