Add bash completion for `docker swarm unlock|unlock-key`

Signed-off-by: Harald Albers <github@albersweb.de>
(cherry picked from commit 07bd5152b3731c108e2dba57b1f51e6609b55ba3)
Signed-off-by: Victor Vieux <vieux@docker.com>

contrib/completion/bash/docker

@@ -2910,6 +2910,8 @@ _docker_swarm() {
 		join
 		join-token
 		leave
+		unlock
+		unlock-key
 		update
 	"
 	__docker_subcommands "$subcommands" && return
@@ -3010,6 +3012,22 @@ _docker_swarm_leave() {
 	esac
 }
 
+_docker_swarm_unlock() {
+	case "$cur" in
+		-*)
+			COMPREPLY=( $( compgen -W "--help" -- "$cur" ) )
+			;;
+	esac
+}
+
+_docker_swarm_unlock-key() {
+	case "$cur" in
+		-*)
+			COMPREPLY=( $( compgen -W "--help --quiet -q --rotate" -- "$cur" ) )
+			;;
+	esac
+}
+
 _docker_swarm_update() {
 	case "$prev" in
 		--cert-expiry|--dispatcher-heartbeat|--max-snapshots|--snapshot-interval|--task-history-limit)