Implemented median and constant strategies in DummyRegressor
Depreciated y_mean_ and y_median. Code is formatted according to pep8
Removed extra lines. Added deprecation warnings for y_mean_
Updated document to reflect changes in the DummyRegressor
Fixed value error. Scalar values are allowed for constant when not multioutput
Done refactoring and necessary changes for multiouput constant strategy. Added tests and updated the documentation.
Changed value error messages to be more informative in constant strategy.
Edited the documentation-unordered list
Implemented additional test cases. Removed the check for lists and numpy arrays in constant strategy.
Refactored the code and added quotes
Recreated test cases with random state
Updated tests. Fixed flake8 errors
fixed pep8 errors in dummy.py
Changed to random_state
Changed documentation in DummyRegressor
Removed one of 'is a regressor' part in the DummyRegressor documentation
Added _LearntSelectorMixin in BaseGradientBoosting
Added extra check to feature importances
Implemented SelectFromModel meta-transformer
Fixed issues in SelectFromModel