yum安装php5.6

多版本php共存

remi安装方法

http://www.servermom.org/how-to-enable-remi-repo-on-centos-7-6-and-5/2790/

配置remi

https://www.mojowill.com/geek/howto-install-php-5-4-5-5-or-5-6-on-centos-6-and-centos-7/

按照php，切换php-fpm

http://www.cnblogs.com/blackpuppy/p/upgrade_php_from_54_to_55_on_centos.html