Revert "remove ml_classifieres from depend"

This reverts commit 95c48b51af89f035a3a6a1dded4a4ccf206eb873.
Revert "Trimmed the branch to only the 3rdparty/sklearn sub directory"

This reverts commit fabbf1710a6df06b20d5f3fc999863269cdcf9a4.
Rebase from 'upstream'
Trimmed the branch to only the 3rdparty/sklearn sub directory
remove ml_classifieres from depend