lbdesign-button-shortcode.php

<?php
/**
* Plugin Name: LBDesign Button Shortcode
* Description: A simple button shortcode
* Author: Lauren Pittenger @ LBDesign
* Version: 1.0
* Last Updated: 2015-03-11
*/

function lbdesign_button($atts, $content = null) {
   extract(shortcode_atts(array('link' => '#', 'color' => '', 'size' => ''), $atts));
   return '<a class="button ' . $color . ' ' . $size . '" href="'.$link.'"><span>' . do_shortcode($content) . '</span></a>';
}
add_shortcode('button', 'lbdesign_button');