code: function(creditCard, success, error) {
      success = success || noop;
      error = error || noop;
      exec(success, error, "CordovaStripe", "createCardToken", [creditCard]);
    }
docs: Create a credit card token
  @param creditCard {module:stripe.CreditCardTokenParams} Credit card information
  @param success {Function} Success callback
  @param error {Function} Error callback