参考文档：
https://newsn.net/say/centos-php72-yum.html#comments
清理冲突的php：
yum -y remove php*
方法一：
rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpmrpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm
方法二：
yuminstallepel-release -yrpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm
安装php72w及其它相关扩展：
方法一（基本）：
yum -yinstallphp72w php72w-cli php72w-fpm php72w-common php72w-devel
方法二（豪华版）：
yum -yinstallphp72w php72w-cli php72w-fpm php72w-common php72w-devel php72w-embedded php72w-gd php72w-mbstring php72w-mysqlnd php72w-opcache php72w-pdo php72w-xml
php-fpm相关服务命令：
systemctlenablephp-fpm.service
systemctl start php-fpm.service
systemctl stop php-fpm.service
systemctl restart php-fpm.service
