In cases where there is high latency (ie, not-local network)
`waitExitOrRemoved` was not receiving events for short-lived containers.
This caused the client to hang while waiting for a notification that the
container has stopped.
This happens because `client.Events()` returns immediately and spins a
goroutine up to process events. The problem here is it returns before
the request to the events endpoint is even made.
Even without high-latency issues, there is no guarantee that the
goroutine is even scheduled by the time the function returns.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
