Fix #9: RDoc::Markup::Paragraph objects have no 'each' method.

Instead, they have a 'parts' method that returns
an enumerator. This patch uses that enumerator to walk
through the authors and append them to the authors
hash.
Removing 1.9.2 support
Merge branch 'master' of https://github.com/petems/puppet-doc-lint
Merge pull request #10 from diranged/issue-9

Fix #9: RDoc::Markup::Paragraph objects have no 'each' method.