Update Install-CentOS-RHEL-6.5-AdminNode.md

This is to bring RHEL-6.5 Admin Node documentation on Github up to par with documentation on wiki.opencrowbar.org
https://wiki.opencrowbar.org/display/OCBP/OpenCrowbar+RPM+deployment+on+CentOS+6.5
Merge pull request #105 from thehybridtechnician/patch-1

+2 docs only, Update Install-CentOS-RHEL-6.5-AdminNode.md