Update on listen address

I had problem on connecting to the container and after investigations I found that it's because program is listening for connections on `localhost` which is good to listen on any interface.
So I changed the `localhost` to `0.0.0.0` and it worked, Now I can connect to container.

main.go

@@ -21,7 +21,7 @@ func main() {
 		delay      = 1
 		limit      = 300
 		usersLimit = 300
-		listenAddr = "localhost:8080"
+		listenAddr = "0.0.0.0:8080"
 		g          = graph.New()
 		showLast   = false
 	)