Install epel
From KlavoWiki
CentOS 7
cd /usr/src wget http://dl.fedoraproject.org/pub/epel/beta/7/x86_64/epel-release-7-0.2.noarch.rpm yum -y install epel-release-7-0.2.noarch.rpm
CentOS 6
rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm