运行composer出现do not run Composer as root/super user!
curl -sS https://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer
composer -V
意思是不要在root超级用户下执行，所以就更换一个用户吧，如下，就不会报这个提示了
useradd zouke
passwd zouke
国内镜像http://packagist.phpcomposer.com不能进行访问，国外镜像访问速度也很慢
使用 Composer 镜像加速
composer config -g repo.packagist composer https://packagist.laravel-china.org
或
composer config -g repo.packagist composer https://packagist.phpcomposer.com
参考文章：
linux下composer小记：Do not run Composer as root/super user!
国内镜像http://packagist.phpcomposer.com不能进行访问
