added mising registration url on nav bar

Author: Bibhas

_layouts/homepage.html

@@ -30,7 +30,7 @@ <h1 class="logo">PyCon India 2014, Bangalore</h1>
     <div class="container">
       <a href="index.html" class="logo"><h1>PyCon India 2014, Bangalore</h1></a>
       <a class="mobile_icon"></a>
-      <!-- <a href="" class="btn-boxy buy-tickets">Buy Tickets</a> -->
+      <a href="http://pyconindia2014.doattend.com/" target="_blank" class="btn-boxy buy-tickets">Buy Tickets</a>
       <nav class="top-navigation" role="navigation">
         <ul>
           <!-- <li class="speakers">