Revert "remove ml_classifieres from depend"

This reverts commit fb1c755e016d2a3275b512a330996f0fa43d90fd.
Revert "Trimmed the branch to only the 3rdparty/sklearn sub directory"

This reverts commit 1596bfa1192f35528eaee43a6b072d0d626e4529.
Rebase from 'upstream' (no changes)
Trimmed the branch to only the 3rdparty/sklearn sub directory
remove ml_classifieres from depend