title: Rails: how to enable PaperTrail auditing for tags
body: <p>I have a Rails 4.2 app and I'd like to keep audit history for tags by using PaperTrail.</p>
  
  <p>Ideally the tags would be logged as if they were simply an attribute of the tagged model i.e. Model#tag_list.</p>
  
  <p>I have enabled logging of Taggings by putting this in an initializer:</p>
  
  <pre><code>module ActsAsTaggableOn
    class Tagging
      has_paper_trail
    end
  end
  </code></pre>
  
  <p>... This does create versions for the Tagging but does not give me the desired behavior which is have the tags appear as simply a tag_list attribute of the tagged model.</p>