add challenge set CM+T

CrossWOZ.py

@@ -162,12 +162,6 @@ class CrossWOZ(datasets.GeneratorBasedBuilder):
             # If there's a common (input, target) tuple from the features,
             # specify them here. They'll be used if as_supervised=True in
             # builder.as_dataset.
-            splits={
-                datasets.Split.TRAIN: "train",
-                datasets.Split.VALIDATION: "val",
-                datasets.Split.TEST: "test",
-                "challenge.CM+T": "CM+T dialogs in the test set"
-            },
             supervised_keys=None,
             # Homepage of the dataset for documentation
             homepage=_HOMEPAGE,