Revert "remove ml_classifieres from depend"

This reverts commit d4507f780c376d04aff1e80f07eef416d8436b82.
Revert "Trimmed the branch to only the 3rdparty/sklearn sub directory"

This reverts commit 05d920d7b93a176749584a59d6d994ddd6bc5844.
Rebase from 'upstream' (no changes)
Trimmed the branch to only the 3rdparty/sklearn sub directory
remove ml_classifieres from depend