Previously, only a few CENTOS server were used. Now that the number of CENTOS machines has increased, yum-cron is being used to automatically push out the updates.
https://github.com/treydock/puppet-yum_cron
The updates should be installed, not just downloaded, so the check_only option is set to no. The code that was used to include the module in the puppet manifest is below.
class { 'yum_cron':
check_only => 'no',
}