composer 安装以及换源（国内源，阿里源，腾讯源）

composer 还原命令如下

composer config -g repo.packagist composer +网址

1.腾讯云composer镜像

composer config -g repos.packagist composer https://mirrors.cloud.tencent.com/composer/

2.阿里云composer镜像（30秒刷新一次全国Cdn缓存）

composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/

3.第三方全国composer镜像

# 中国全量镜像
composer config -g repo.packagist composer 
https://packagist.phpcomposer.com