We can do that now as we're no longer carrying archive/tar.
Note that latest vndr removes vendor/ subdir so we don't have to,
thus the change in hack/validate/vendor.
While at it, re-run a new vndr version to make sure everything
that should be there is.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin