Respect the RACE_DETECTION env var
Respect the RACE_DETECTION env var

In guardian tests.

[finishes #151713778]

Signed-off-by: Craig Furman <82b4b6d2372fcea863d8fd21c02d40060d303650@pivotal.io>

cloudfoundry-incubator/guardian-release,cloudfoundry-incubator/guardian-release,cloudfoundry-incubator/guardian-release