错误：
Warning: This development build of composer is over 60 days old. It is recommend ed to update it by running "E:\xampp\PHP\composer.phar self-update" to get the l atest version.
Failed to decode response: zlib_decode(): data error retrying with degraded mode, check https://getcomposer.org/doc/articles/troubleshooting.md#degraded-mode for more info
composer selfupdate
composer安装请参考http://www.xiaoshu168.com/php/167.html
