Fix PaymentIntent cancelation

[Patrick-Kladek]

Description

While using this library I noticed canceling a payment intent was not possible. More specifically was the cancellation_reason not supported. After checking the docs I've updated the enum and can confirm it works now.

Tasks

• update PaymentIntentCancellationReason enum

Infos for Reviewer

I'm using the Payment Intent in combination with Stripe Connect. I couldn't verify if the behavior is different with another stripe product, however it says the same in the documentation here: https://stripe.com/docs/api/payment_intents/cancel

Here is the error returned from the API:

The cancellation_reason provided in the request is not a valid user provided reason. 
Please try canceling again with one of duplicate`, `fraudulent`, `requested_by_customer`
or `abandoned.

{
  "cancellation_reason": "automatic"
}

[Andrewangeta]

One comment.

[Patrick-Kladek]

I wasn't aware that this enum was used for decoding responses. Thanks for fixing and merging this.