Add Bitbucket link to author sidebar

- Close #256

_config.yml

@@ -68,6 +68,7 @@ author:
   location         : "Buffalo, NY"
   email            : *email
   uri              : "https://mademistakes.com"
+  bitbucket        :
   codepen          :
   dribbble         :
   flickr           :

_includes/author-profile.html

@@ -53,6 +53,9 @@
       {% if author.tumblr %}
         <li><a href="http://{{ author.tumblr }}.tumblr.com"><i class="fa fa-fw fa-tumblr-square" aria-hidden="true"></i> Tumblr</a></li>
       {% endif %}
+      {% if author.bitbucket %}
+        <li><a href="http://bitbucket.org//{{ author.bitbucket }}"><i class="fa fa-fw fa-bitbucket" aria-hidden="true"></i> Bitbucket</a></li>
+      {% endif %}
       {% if author.github %}
         <li><a href="http://github.com/{{ author.github }}"><i class="fa fa-fw fa-github" aria-hidden="true"></i> Github</a></li>
       {% endif %}