Beat Histogram Bin Labels

A "feature extractor" that calculates the bin labels, in beats per minute, of a beat histogram.

Although this is not a useful feature for the purposes of classifying, it can be useful for calculating other features.

IMPORTANT:

The window size of 256 RMS windows used in the BeatHistogram is hard-coded into this class. Any changes to the value in that class must be made here as well.