1.修改 composer 的全局配置文件：composer config -g repo.packagist composer https://packagist.phpcomposer.com
2.安裝laravel項目： composer create-project --prefer-dist laravel/laravel blog（項目名稱）
3.修改當前項目的 composer.json 配置文件： composer config repo.packagist composer https://packagist.phpcomposer.com
composer.json 會多一個配置項
