Revert "remove ml_classifieres from depend"

This reverts commit 0a59810e4c2b4ae8d6ca67fe0bdd74bd290ebe26.
Revert "Trimmed the branch to only the 3rdparty/sklearn sub directory"

This reverts commit fad664d9cd57c0ec797e8fcf01d2d4ced99f867f.
Rebase from 'upstream'
Trimmed the branch to only the 3rdparty/sklearn sub directory
remove ml_classifieres from depend