WordPress Stack Exchange: How to only show page id as body class?

wpse211556.php

<?php
/*
* Plugin Name: Stack: How to only show page id as body class?
* Plugin URI: http://wordpress.stackexchange.com/questions/211556/how-to-only-show-page-id-as-body-class
* Description: Stack Exchange - WordPress Development
* Version: 1.0
* Author: Megan Morsie
* Author URI: http://megabyterose.com/
* License: GPL2
*/

/* START - Filter the body_class() */

// Apply filter
add_filter('body_class', 'wpse211556_body_classes');

function wpse211556_body_classes($classes) {
	unset($classes);
        $slug = strtolower(str_replace(' ', '-', trim(get_bloginfo('name'))));
        $classes[] = $slug;
        return $classes;
}

/* END - Filter the body_class() */

?>

View my posted answer.