Don't print cf auth command in nfsbrokerpush output
Don't print cf auth command in nfsbrokerpush output

- it contains sensitive credentials

[#161849234](https://www.pivotaltracker.com/story/show/161849234)

cloudfoundry-incubator/nfs-volume-release,cloudfoundry-incubator/nfs-volume-release,cloudfoundry-incubator/nfs-volume-release