title: How to custom actions method helper in active admin
body: <p>when i define </p>
  
  <pre><code>  index do
      column :id, :sortable =&gt; :id
      column :title
      column :avatar do |post|
        div style: "text-align:center;" do 
          image_tag post.avatar_url(:thumb), :class =&gt; "img-responsive"
        end 
      end
      column :published
      actions
    end 
  </code></pre>
  
  <p>"actions" general 3 links (view, edit, and delete)
   I want to add target="_parent" for 3 links above.</p>
  
  <p>example:</p>
  
  <pre><code>&lt;a class="edit_link member_link" href="/admin/places/5/edit?locale=en"&gt;Edit&lt;/a&gt;
  </code></pre>
  
  <p>to</p>
  
  <pre><code>&lt;a class="edit_link member_link" href="/admin/places/5/edit?locale=en" target="_parent"&gt;Edit&lt;/a&gt;
  </code></pre>
  
  <p>How to do this?</p>