centos7 default PHP5.4, version is too low, many require at least PHP5.5
1, see the PHP components have been installed
yum list installed| grep php
php.x86_64 5.4.16-46.el7 @base php-cli.x86_64 5.4.16-46.el7 @base php-common.x86_64 5.4.16-46.el7 @base
2, uninstall the original PHP components
yum remove php.x86_64 php-cli.x86_64 php-common.x86_64
3, install a new source
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
4, installation PHP5.5
yum install php55w.x86_64 php55w-cli.x86_64 php55w-common.x86_64 php55w-gd.x86_64 php55w-ldap.x86_64 php55w-mbstring.x86_64 php55w-mcrypt.x86_64 php55w-mysql.x86_64 php55w-pdo.x86_64
5, check the version
php -v
PHP 5.5.38 (cli) (built: Jul 21 2016 12:25:20) Copyright (c) 1997-2015 The PHP Group Zend Engine v2.5.0, Copyright (c) 1998-2015 Zend Technologies