title: ActionController::UnknownFormat when sending plain text
body: <p>I'm riding Rail4 and trying to send some plain text down with a GET request:</p>
  
  <pre><code>def get_text
    respond_to do |format|
      format.text { render :text =&gt; "huh" }
    end
  end
  </code></pre>
  
  <p>But I end up with <code>ActionController::UnknownFormat</code> which I have frustrating discovered is Rails' funny way of saying 406 not acceptable.</p>
  
  <p>What is going on here?</p>