LightGBM

v3.2.0 release (#3872)

* Update VERSION.txt

* update appveyor.yml and configure

* fix Appveyor builds

Co-authored-by: James Lamb <jaylamb20@gmail.com>
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>
Co-authored-by: StrikerRUS <nekit94-12@hotmail.com>