ColumnTransformer generalization to work on empty lists (scikit-learn… …#12084)

MNT rc version 

Release 0.19.2 

TST Improve SelectFromModel tests (scikit-learn#9733) Should fix one of the issues in scikit-learn#9393

Release 0.19.0 

Release 0.19b2 

0.19b1 release tag 

DOC typos in whats_news.rst [ci skip] 

bump version, added whatsnew 

skip tree-test on 32bit