* we do not transform y
* more
* added Deprecation Warning to transform() to remove Y parameter
* more
* ENH ensure FunctionTransformer's transform/inverse_transform doesn't permit y
* Undo changes to pls_. It will be done in a separate PR (see #9160)
* flake8
* Update whatsnew
* Fully undo PLS changes
* copyedit doc
* give the module an underscore (we should do this to all private modules...)
* use public import path in test
* change all logs to log1p to prevent warning in test and because it's
genuinely useful for frequency data
* what's new