ERROR : Error during puppet run : err: /Stage[main]//Package[openstack-selinux]/ensure: change from absent to present failed: Execution of '/usr/bin/yum -d 0 -e 0 -y install openstack-selinux' returned 1: Error: Nothing to do
This error message says that there is no such package in yum repositories as openstack-selinux. Check your yum repos and find out what repo has to be added.
As far as I see online, you simply need to add OpenStack repo with:
yum install http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm