在執行 composer update 時，報錯
You made a reference to a non-existent script @php artisan package:discover
網上說是 composer 的版本太低，查看了一下當前安裝的版本
composer -V Composer version 1.2.1 2016-09-12 11:27:19 解決方法，升級 composer 版本
composer selfupdate Updating to version 1.6.3 (stable channel). Downloading: 100% Use composer self-update --rollback to return to version 1.2.1