Revert "Don't install EPEL rpm on CentOS 6.4"

This reverts commit 09f4ff95f40290978b0b0ae17ebc110e9a0fb804.

The EPEL rpm issue was a temporary problem with Rackspace's images.

Change-Id: Ic891c9be13ca99351214133fcbb41f0b42b5a333
Merge "Revert "Don't install EPEL rpm on CentOS 6.4""