app/views/layouts/welcome.html.haml
!!!
%html{xmlns: "http://www.w3.org/1999/xhtml", "xmlns:fb" => "http://www.facebook.com/2008/fbml", "xmlns:og" => "http://ogp.me/ns#", :lang => "en"}
= render 'head'
%body{ class: body_classes }
= render "application/header"
= yield
= render 'footer'