composer config -g repo.packagist composer https://packagist.phpcomposer.com
Laravel China 镜像完成历史使命，将于2019年9月停用
https://learnku.com/articles/30758
感谢Laravel China！！！
阿里云 Composer 全量镜像
https://developer.aliyun.com/composer
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/
阿里牛B！！！