linspace -> arange in very_bad_melody_extractor (#37)
linspace -> arange in very_bad_melody_extractor (#37)

`linspace` has the following prototype
`numpy.linspace(start, stop, num=50, endpoint=True, retstep=False, dtype=None, axis=0)`

whereas `arange` has the following prototype
`numpy.arange([start, ]stop, [step, ]dtype=None)`

i'm pretty sure that the authors means to use a `step=0.01` and not `num=0.01`
mir-dataset-loaders/mirdata