替换镜像源：
composer config -g repo.packagist composer 源地址url
官方默认源：
composer config -g repo.packagist composer https://repo.packagist.org
镜像推荐：
阿里云 Composer 镜像 https://mirrors.aliyun.com/composer/ 阿里云
腾讯云 Composer 镜像 https://mirrors.cloud.tencent.com/composer/ 腾讯云