Merge pull request #6461 from albers/completion-ps--all

Add bash completion for `ps --all|-a`

contrib/completion/bash/docker-compose

@@ -361,7 +361,7 @@ _docker_compose_ps() {
 
 	case "$cur" in
 		-*)
-			COMPREPLY=( $( compgen -W "--help --quiet -q --services --filter" -- "$cur" ) )
+			COMPREPLY=( $( compgen -W "--all -a --filter --help --quiet -q --services" -- "$cur" ) )
 			;;
 		*)
 			__docker_compose_complete_services