* ENH Accept keyword parameters to hyperparameter search fit methods
Deprecate ``fit_params`` as a constructor argument to the hyperparameter search classes and instead accept keyword parameters to the ``fit`` methods. This makes the ``fit`` methods of these functions conform to the Estimator API and allows the use of hyperparameter search functions in other CV utility functions such as ``cross_val_predict``.
* CR: Expanded tests, remove deprecated use in Ridge
* Make tests consistent in Python 2 and 3
* BF: issue 5522 (cloning objects with pandas.Dataframe attributes)
* super conservative fix, pending GP and VBGMM fixes.
* TST improved test for df param
* add deprecation warning, add whatsnew entry
* fixed place of deprecation warning, added test for deprecation warning.
* pep8
* fix whitespace error
Bartosz Michałowski