fixed a bug in cv composer

cdplib/ml_validation/CVComposer.py

@@ -70,8 +70,8 @@ class CVComposer:
 
         if use_index:
 
-            cv = self.dummy_cv(train_index=X_train.index,
-                               test_index=X_test.index)
+            cv = self.dummy_cv(train_set_index=X_train.index,
+                               test_set_index=X_test.index)
 
             X = pd.concat([X_train, X_test], ignore_index=False, axis=0)