Change the separator in between the post categories

functions.php

<?php
// Paste the code BELOW this line into your child theme functions.

/**
 * Change the separator in between the post categories
 *
 * @author Reasons to Use Genesis
 * @link http://reasonstousegenesis.com/list-categories/
 */
add_filter( 'genesis_post_info', 'rtug_category_list_sep' );
function rtug_category_list_sep() {
	return '[post_categories sep="! "]';
}