title: Woocommerce default role and role after purchase
body: <p>I found <a href="https://stackoverflow.com/questions/19681523/woocommerce-changing-user-role-when-order-is-complete">this thread</a> but it doesn't exactly do what I'm looking for. </p>
  
  <p>My question is, how can I change the default Woocommerce role "customer" to, e.g. "Subscriber" for new registered users. 
  And then, if user checks out (purchases product), change the role from "Subscriber" to "Customer". </p>
  
  <p>I'm asking this as I want to show different content per user roles: "registered customer" and "subscribed (paid) customer". </p>