Revert "hacking should conform with OS requirements"

Pinning six for ceilo has messed everything up, for the sake of getting
things unblocked, unpin six, at least for now.

This reverts commit e83339e5dcb210eb3d97f4de70096321748851cb.

Change-Id: Id7a5b8e2fe7a29714cf087d34d9e0f1207906f3d