<div id="single_post_nav" class="row">
    <div class="col-md-6">
        <?php
        if (is_attachment()) {
            previous_image_link();
        } else {
            previous_post_link('%link', __( '&laquo;', 'Previous post link', 'nimbus') . ' %title');
        }
        ?>
    </div>
    <div class="col-md-6 text-right">
        <?php
        if (is_attachment()) {
            next_image_link();
        } else {
            next_post_link('%link', '%title ' . __( '&raquo;', 'Next post link', 'nimbus'));
        }
        ?>
    </div>
</div>