Add a predictions algorithm useful for deeplearning

bob/pad/base/algorithm/Predictions.py

+from bob.pad.base.algorithm import Algorithm
+
+
+class Predictions(Algorithm):
+    """An algorithm that takes the precomputed predictions and uses them for
+    scoring."""
+
+    def __init__(self, **kwargs):
+        super(Predictions, self).__init__(
+            **kwargs)
+
+    def score(self, predictions):
+        # Assuming the predictions are the output of a softmax layer
+        return [predictions[1]]