Merge branch 'rss_icon' into 'master'

"RSS" in blog switched to RSS icon

Fixes #245

Switched the RSS text for an icon.

See merge request !583

source/_includes/newsletter_signup.html

@@ -4,7 +4,9 @@
     on Twitter.
     <a href="/atom.xml" class="rss-btn">
-      <button class="btn btn-sm btn-default">RSS</button>
+      <button class="btn btn-sm btn-default" data-toggle="tooltip" data-placement="right" title="RSS">
+        <i class="fa fa-rss"></i>
+      </button>
     </a>
   </div>

source/javascripts/blog.js

+$(document).ready(function() {
+  $('[data-toggle="tooltip"]').tooltip()
+});