use mastodon icon

Author: bast

templates/footer.html

@@ -23,7 +23,7 @@ <h4>Follow us</h4>
         <a href="https://github.com/coderefinery" target="_blank" uk-icon="icon: github">GitHub</a>
       </li>
       <li>
-        <a rel="me" href="https://fosstodon.org/@coderefinery" target="_blank" uk-icon="icon: social">Mastodon</a>
+        <a rel="me" href="https://fosstodon.org/@coderefinery" target="_blank" uk-icon="icon: mastodon">Mastodon</a>
       </li>
       <li>
         <a href="https://twitter.com/coderefine" target="_blank" uk-icon="icon: twitter">Twitter</a>