swarm-smoke: add debug flag (#1428)

cmd/swarm-smoke/main.go

@@ -48,6 +48,7 @@ var (
 	timeout    int
 	single     bool
 	onlyUpload bool
+	debug      bool
 )
 
 func main() {
@@ -114,6 +115,11 @@ func main() {
 			Usage:       "whether to only upload content to a single node without fetching",
 			Destination: &onlyUpload,
 		},
+		cli.BoolFlag{
+			Name:        "debug",
+			Usage:       "whether to call debug APIs as part of the smoke test",
+			Destination: &debug,
+		},
 	}
 
 	app.Flags = append(app.Flags, []cli.Flag{