automatically detect labels and bins

[felixbur]

I guess it would be better if the labels would not need to be given explicitly but read from the datafile automatically. I meant that the labels [anger, disgust, happy...] are already in the data. Currently you have to tell nkululeko which labels to use, but if you want all, that shouldn't be necessary

For regression I would define default binning e.g. automatically assign three bins: (low, medium, high), and use the borders so they are equally distributed