text: Title: Error: Algorithm should either be a classifier to be used with response_method=predict_proba or the response_method should be 'predict'
  Body: Hi!
  
  Recently I started getting this error (or warning?) with binary classification.
  Minimal code to reproduce the problem:
  
  ```
  from supervised import AutoML
  
  if __name__ == '__main__':
      from sklearn.datasets import make_classification
      X, y = make_classification(n_samples=100000, n_features=20, n_redundant=2)
      from sklearn.model_selection import train_test_split
      X_train, X_test, y_train, y_test = train_test_split( X, y, test_size=0.3)
      automl = AutoML(eval_metric="accuracy")
      automl.fit(X_train, y_train)
      automl.report()
  ```
  I get multiple messages:
  ```
  DecisionTreeAlgorithm should either be a classifier to be used with response_method=predict_proba or the response_method should be 'predict'. Got a regressor with response_method=predict_proba instead.
  Problem during computing permutation importance. Skipping ...
  ```
  
  Is it a new bug or we can just ignore it?
  Thank you!
  