Set version 0.1.0 (#21)

diff --git a/swctl/main.go b/swctl/main.go
index 20efced..113c2bb 100644
--- a/swctl/main.go
+++ b/swctl/main.go
@@ -46,6 +46,7 @@
 func main() {
 	app := cli.NewApp()
 	app.Usage = "The CLI (Command Line Interface) for Apache SkyWalking."
+	app.Version = "0.1.0"
 
 	flags := []cli.Flag{
 		altsrc.NewStringFlag(cli.StringFlag{