almost working...
working poisson vocoder
poisson vocoder working
ENH: Add warning for bad rt_chisq
almost working...
working poisson vocoder
poisson vocoder working
added zero-phase
WIP: updating vocoder examples
Merge branch 'vocoder-two-point-oh' of github.com:drammock/expyfun into vocoder-two-point-oh

Conflicts:
	expyfun/stimuli/_vocoder.py
working noise/tone/click vocoder example
better docs
fix vocoder test
cleanup unused logger import
reduce RMS to avoid clipping on the sample
simplified example to use built-in poisson generation
allow np.random.RandomState to be passed as seed
update zero_phase to use filtfilt
better docs
better tests for random seed