title: Rails route for non-resource for csv
body: <p>I have a method called "revisions", and I want to be able use the same logic but output to csv.  I think I'd like to use the FasterCSV gem.  What I need is to what to add to my routes in order to get a route for both the html and the csv outputs.  I'd like my urls to be something like this:</p>
  
  <pre><code>invoices/51/revisions
  invoices/51/revisions.csv
  </code></pre>
  
  <p>Thoughts?</p>
  
  <p>Thanks much!</p>