Replace secrets with join tokens

Implement the proposal from
https://github.com/docker/docker/issues/24430#issuecomment-233100121

Removes acceptance policy and secret in favor of an automatically
generated join token that combines the secret, CA hash, and
manager/worker role into a single opaque string.

Adds a docker swarm join-token subcommand to inspect and rotate the
tokens.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
Upstream-commit: 2cc5bd33eef038bf5721582e2410ba459bb656e9
Component: engine

components/engine/api/client/node/cmd.go

@@ -23,7 +23,6 @@ func NewNodeCommand(dockerCli *client.DockerCli) *cobra.Command {
 		},
 	}
 	cmd.AddCommand(
-		newAcceptCommand(dockerCli),
 		newDemoteCommand(dockerCli),
 		newInspectCommand(dockerCli),
 		newListCommand(dockerCli),