changed "train" to "fit" in the super call (#185)

Because of the name change from of the fitting method from "train" to "fit", there are some inconsistencies. Changed the super call, is it would break there

Author: fanconic

src/ydata_synthetic/synthesizers/regular/wgangp/model.py

@@ -142,7 +142,7 @@ def fit(self, data, train_arguments: TrainParameters, num_cols: List[str], cat_c
             num_cols: List of columns of the data object to be handled as numerical
             cat_cols: List of columns of the data object to be handled as categorical
         """
-        super().train(data, num_cols, cat_cols)
+        super().fit(data, num_cols, cat_cols)
 
         processed_data = self.processor.transform(data)
         self.data_dim = processed_data.shape[1]