Fixes issues with salsa which is used in swarmkit, see
https://github.com/docker/swarmkit/pull/2838
As we only encrypt small values this should be a non breaking change.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
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>