!act #16125 Timeout Calls through CircuitBreaker.

CircuitBreaker used to wait idenfinitly for a call and only compare
duration after the facts. It will now throw a TimeoutException.

I don't think that this tests "before call finishes". Perhaps something like:

    Future {
      breaker().withSyncCircuitBreaker {
         Thread.sleep(500.millis.dilated.toMillis)
      }
    }

    within(300.millis) {
      awaitCond(breaker().currentFailureCount == 1, 100.millis.dilated)
    }