app/views/shared/_footer_social.html.erb
<div class="container-fluid">
<div class="col-xs-12 social">
<ul class="navbar-nav social list-unstyled">
<li>
<a class="twitter-share-button"
href="https://twitter.com/intent/tweet"
data-size="large"
data-show-count="false">
Tweet</a>
<script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
</li>
<li>
<div class="fb-share-button" data-href="https://cdr.lib.unc.edu" data-layout="button" data-size="large" data-mobile-iframe="true">
<a target="_blank" href="https://www.facebook.com/sharer/sharer.php?u=https%3A%2F%2Fdevelopers.facebook.com%2Fdocs%2Fplugins%2F&src=sdkpreparse" class="fb-xfbml-parse-ignore">Share</a>
</div>
</li>
</ul>
</div>
</div>
<div id="fb-root"></div>
<script>(function(d, s, id) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) return;
js = d.createElement(s); js.id = id;
js.src = 'https://connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.12';
fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));</script>