Wrong CSI Code for EraseDisplay

according the [Wikipedia](https://en.wikipedia.org/wiki/ANSI_escape_code#Terminal_output_sequences),you may have a mistake with 

```Golang
// EraseDisplay clears the screen
func EraseDisplay(code int) string {
	return Esc + "[" + strconv.Itoa(code) + "2J" //Should be single "J"
}

```

