Revert "remove ml_classifieres from depend"

This reverts commit 1dd55d5f13428a8d350985f9ff9b1be70cd8cdb4.
Revert "Trimmed the branch to only the 3rdparty/sklearn sub directory"

This reverts commit 661a7f57e8d2d1a82a89f41bec076b9501f4135f.
Rebase from 'upstream' (no changes)
Trimmed the branch to only the 3rdparty/sklearn sub directory
remove ml_classifieres from depend