Remove "No Finding" as a class label

[jacobeturpin]

The implementation, as it currently stands, has 15 output labels for the multilabel classification. One of these is the label "No Finding" as presented in the NIH ChestX-Ray14 dataset. It's proposed that the label "No Finding" is removed as a potential binary class. The reasoning is that "No Finding" isn't the presence of a given object/pathology like the other classes. Rather, it's simply the absence of a positive class in any of the other possible labels.