message: Simplify the customer w/ card example
diff: @@ -7,20 +7,16 @@ fn main() {
  let secret_key = env::var("STRIPE_SECRET_KEY").expect("Missing STRIPE_SECRET_KEY in env");
  let client = stripe::Client::new(&secret_key);
  - // Build request params
  + // Define a card for the customer
  + let mut card = stripe::CardParams::default();
  + card.number = "4242424242424242";
  + card.exp_month = "10";
  + card.exp_year = "20";
  +
  + // Define the customer
  let mut params = stripe::CustomerParams::default();
  params.email = Some("jdoe@example.org");
  - params.source = Some(stripe::CustomerSource::Card(
  - stripe::CardParams{
  - object: "card",
  - number: "4242424242424242",
  - exp_month: "02",
  - exp_year: "21",
  -
  - name: None,
  - cvc: None,
  - }
  - ));
  + params.source = Some(stripe::CustomerSource::Card(card));
  // Perform request
  let customer = stripe::Customer::create(&client, params).unwrap();
  