Make the consumer in the throughput tests truly do no work.

[leifp]

Due to reflection, the throughput tests aren't giving the correct impression of the throughput/overhead of the library.

If you add a ^CountDownLatch type hint to the consumer:
https://github.com/clojurewerkz/meltdown/blob/master/test/clojurewerkz/meltdown/throughput_test.clj#L35

This gives me a 10x speedup using RingBufferDispatcher, and the events/second for a no-op consumer are in the millions, as advertised.

[michaelklishin]

I now enabled reflection warnings and there seem to be a whole bunch of other cases where reflection is used (likely not on the hot path, though). Feel free to submit a pull request that correct more of that stuff and thanks for finding this out!