title: Async Sinatra failing with parameters in path
body: <p>I have an async_sinatra application that uses eventmachine in the following way:</p>
  
  <pre><code>aget '/test' do
      EM.defer { body 'test: ' + params[:foo] }
  end
  </code></pre>
  
  <p>When I request the url as <code>/test?foo=bar</code> it yields <code>test: bar</code>, however when I declare the path as <code>aget '/test/:foo' do</code> and attempt to use <code>params[:foo]</code> the request never returns.</p>
  
  <p>Why can't I use in-url parameters in async_sinatra?</p>