vendor github.com/prometheus/client_golang/prometheus/testutil package updating staging godeps
vendor github.com/prometheus/client_golang/prometheus/testutil package
updating staging godeps

Kubernetes-commit: 9632e4349eac7133ec7fa713b14601e9c580356a

kubernetes/sample-apiserver,kubernetes-nightly/sample-apiserver,kubernetes/sample-apiserver,kubernetes-nightly/sample-apiserver