title: Go rand.Intn same number/value
body: <p>Can anyone please tell me why the Go example here:</p>
  
  <p><a href="https://tour.golang.org/basics/1" rel="noreferrer">https://tour.golang.org/basics/1</a></p>
  
  <p>always returns the same value for rand.Intn(10)?</p>