Clarify access for the admin user
Clarify access for the admin user

When trying this out I initially tried logging in as the cluster-admin
user, rather than just using admin. I thing this change should hopefully
help anyone else running into the same issue.

The user is called admin as per
https://github.com/garethr/vagrant-origin/blob/master/scripts/origin-setup.sh#L220

openshift-evangelists/vagrant-origin,openshift-evangelists/vagrant-origin