Add alert box for past version of eclipse

Change-Id: I89aef8a97845734659380c68d089d38cb178ae89
Signed-off-by: Eric Poirier <eric.poirier@eclipse-foundation.org>
diff --git a/index.php b/index.php
index ba1f655..e0baa39 100644
--- a/index.php
+++ b/index.php
@@ -49,6 +49,11 @@
 ?>
 <div class="jumbotron featured-jumbotron margin-bottom-0">
   <div class="container">
+    <div class="alert alert-danger" role="alert">
+      <a href="https://projects.eclipse.org/releases/photon">Photon</a> is
+      a past version of Eclipse. Please visit our <a href="/downloads/">download</a>
+      page for the latest version of Eclipse.
+    </div>
     <div class="row">
       <div class="col-md-20 col-md-offset-2 col-sm-18 col-sm-offset-3">
         <h1 class="jumbotron-title"><span class="small-title">Eclipse</span><br> <span class="big-title">Photon</span></h1>