Before the CentOS mirror of NetEase, aliyun CentOS upgrade to the latest version, has yet to begin a formal development of own projects, then upgrade all the appropriate environment to the highest.
See CentOS versions:
[root@iZ23d ~]# cat /etc/centos-release
CentOS Linux release 7.2.1511 (Core)
1、 Deleting a previous PHP version :
[root@iZ23d ~]# systemctl restart httpd.service