Check args numbers before application start

Add a general args number validator for all client commands.

Signed-off-by: Zhang Wei <zhangwei555@huawei.com>

kill.go

@@ -69,6 +69,9 @@ signal to the init process of the "ubuntu01" container:
 		},
 	},
 	Action: func(context *cli.Context) error {
+		if err := checkArgs(context, 2, exactArgs); err != nil {
+			return err
+		}
 		container, err := getContainer(context)
 		if err != nil {
 			return err