Changes to Create Discount

added the new optional request property oneOf[subschema #1: DiscountFixedCreate]/max_redemptions_per_customer

added the new optional request property oneOf[subschema #2: DiscountPercentageCreate]/max_redemptions_per_customer

added the required property oneOf[subschema #1: DiscountFixedOnceForeverDuration]/max_redemptions_per_customer to the response with the 201 status

added the required property oneOf[subschema #2: DiscountFixedRepeatDuration]/max_redemptions_per_customer to the response with the 201 status

added the required property oneOf[subschema #3: DiscountPercentageOnceForeverDuration]/max_redemptions_per_customer to the response with the 201 status

added the required property oneOf[subschema #4: DiscountPercentageRepeatDuration]/max_redemptions_per_customer to the response with the 201 status