Skip EPEL & RDO install for CI nodes
Skip EPEL & RDO install for CI nodes

If the nodepool info file is around, assume we're on a OpenStack CI
node and skip re-installing EPEL & RDO

Change-Id: Ife80af015b26514098e0633f568e3da35b9eea8c

richliu/devstack,group-policy/devstack,noironetworks/devstack,nawawi/openstack,bswartz/devstack,Mahito/devstack,Mahito/devstack,bswartz/devstack,nawawi/openstack,richliu/devstack,dtroyer/devstack,bigswitch/devstack,noironetworks/devstack,bigswitch/devstack,group-policy/devstack,dtroyer/devstack,openstack-dev/devstack,openstack-dev/devstack