Handle reservation failure

[ipwnponies]

When attempting to reserve a meal that's booked out, the response is HTTP 400, with response:

{
  "error": "ERROR_AMOUNT_LIMIT"
}

It would be great handle this case, instead of retrying. Also will empower #9, since we can differentiate between when to retry and when to fallback to second choice.

mealpy/mealpy/mealpy.py

Lines 129 to 130 in 5fc5bc7

	request = self.session.post(RESERVATION_URL, json=reserve_data)
	return request.status_code

[ipwnponies]

I'm going to add more responses that could be handled here. We can split the ticket if it gets large or when we get to it.

Kitchen closed

{
  "error": "ERROR_KITCHEN_CLOSED"
}

Another meal is already reserved

{
  "error": "ERROR_RESERVATION_LIMIT"
}