gpu support and sklearn support about deep-forest HOT 12 OPEN

/home/pbc/anaconda3/envs/cuda9/lib/python3.6/site-packages/sklearn/model_selection/_validation.py:700: UserWarning: Scoring failed. The score on this train-test partition for these parameters will be set to nan. Details: 
Traceback (most recent call last):
[CV 1/5] END predictor=xgboost; accuracy: (test=nan) average_precision: (test=nan) f1: (test=nan) roc_auc: (test=nan) total time=10.0min
  File "/home/pbc/anaconda3/envs/cuda9/lib/python3.6/site-packages/sklearn/metrics/_scorer.py", line 56, in _cached_call
    return cache[method]
KeyError: 'decision_function'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/home/pbc/anaconda3/envs/cuda9/lib/python3.6/site-packages/sklearn/metrics/_scorer.py", line 334, in _score
    y_pred = method_caller(clf, "decision_function", X)
  File "/home/pbc/anaconda3/envs/cuda9/lib/python3.6/site-packages/sklearn/metrics/_scorer.py", line 58, in _cached_call
    result = getattr(estimator, method)(*args, **kwargs)
AttributeError: 'CascadeForestClassifier' object has no attribute 'decision_function'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/home/pbc/anaconda3/envs/cuda9/lib/python3.6/site-packages/sklearn/model_selection/_validation.py", line 687, in _score
    scores = scorer(estimator, X_test, y_test)
  File "/home/pbc/anaconda3/envs/cuda9/lib/python3.6/site-packages/sklearn/metrics/_scorer.py", line 88, in __call__
    *args, **kwargs)
  File "/home/pbc/anaconda3/envs/cuda9/lib/python3.6/site-packages/sklearn/metrics/_scorer.py", line 353, in _score
    y_pred = self._select_proba_binary(y_pred, clf.classes_)
AttributeError: 'CascadeForestClassifier' object has no attribute 'classes_'
  UserWarning,