allow callables to pandas.corr in correlation selection transformers (#279)

* feat(smart_correlation_selection): callable methon in SmartCorrelatedSelection

* tests(test_smart_correlation_selection): test callable method

* test(test_drop_correlated_features): test callable method

* fix(smart_correlation_selection): two positional_or_kewyword input arguments

* smart/drop correlation examples

* fix flake8 errors

* remove callable method check

* fix(conftest): return method not wrapper

* fix(smart_correlation_selection): pandas raise method error

* style errors

* changes indentation in docstrings

* removed redundant df from file

* meaningful name to random uniform

Co-authored-by: Soledad Galli <[email protected]>

Author: TremaMiguel