Shoestrap 3 - add previous/next links in the bottom of single posts

functions.php

<?php
add_action( 'shoestrap_in_article_bottom', 'custom_prev_next_links' );
function custom_prev_next_links() {
$prev_post = get_previous_post();
$next_post = get_next_post();
	if (!empty( $prev_post )) {
	  echo '<a class="pull-left" href="'. get_permalink( $prev_post->ID ) .'"><<< '. $prev_post->post_title .'</a>';
	}
	if (!empty( $next_post )) {
	  echo '<a class="pull-right" href="'. get_permalink( $next_post->ID ) .'">'. $next_post->post_title .' >>></a>';
	}
}