centos yum安装php5.6.19 remi源按照
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