title: Rabl, remove parent element of children
body: <p>could anyone help me get rid of the "item" element within "items</p>
  
  <p>the output should be:<br>
  <code>"list":{ "items":[ { { data1: "test" } , { data2: "test2" } } }</code></p>
  
  <pre><code>collection @list
  
  child :items =&gt; :items do
    attributes :place_id
  end
  
  child :items do
    child :place do |place|
      extends 'places/place', object: place
    end
  end
  </code></pre>
  
  <p>current output:<br>
  <code>"list":{ "items":[{ "item":{data1: "test"} "item":{ data2: "test2"}}}</code></p>