Intermittent test failures in `internal/redis.TestWatchKeyAlreadyChanged`
e.g. https://gitlab.com/gitlab-org/gitlab-workhorse/builds/11363653
I see it more often in go1.6, @bkc has reproduced locally (on 1.7?) by running the tests in a tight loop.
Everything points to a race in redigomock, KeyWatcher
itself, or our test.