Add bash completion for experimental `docker deploy`

Signed-off-by: Harald Albers <github@albersweb.de>
(cherry picked from commit 10f567ec6a)
Signed-off-by: Victor Vieux <victorvieux@gmail.com>

contrib/completion/bash/docker

@@ -1882,6 +1882,10 @@ _docker_daemon() {
 	esac
 }
 
+_docker_deploy() {
+	__docker_is_experimental && _docker_stack_deploy
+}
+
 _docker_diff() {
 	_docker_container_diff
 }
@@ -3865,6 +3869,7 @@ _docker() {
 	)
 
 	local experimental_commands=(
+		deploy
 	)
 
 	# These options are valid as global options for all client commands