未来往事
如果之前已经安装过php环境，升级请先卸载一下。
yum -y remove php*
由于linux的yum源不存在php7.x，所以我们要更改yum源
rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm
yum 安装php72w和各种拓展，选自己需要的即可
yum -y install php72w php72w-cli php72w-common php72w-devel php72w-embedded php72w-fpm php72w-gd php72w-mbstring php72w-mysqlnd php72w-opcache php72w-pdo php72w-xml php72w-intl
