Update README.md to reflect changes for credentials [#135174273](https://www.pivotaltracker.com/story/show/135174273)
Update README.md to reflect changes for credentials
[#135174273](https://www.pivotaltracker.com/story/show/135174273)

Signed-off-by: Peter Blum <508acb8bed17cb72405cd38c72851e4e4a858be5@emc.com>

cloudfoundry-incubator/cephfs-bosh-release,cloudfoundry-incubator/cephfs-bosh-release