Remove data races in cluster/monitor test
Remove data races in cluster/monitor test

[#128188319]

Signed-off-by: Natalie J. Bennett <e5fc036b158c983344048075b2b1e5c6083fede5@pivotal.io>

cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard