Reservations should use AAdvantage Number and not Mongo _id

[johnkahn]

Pre-requisites:

• Yes, I looked through both open and closed issues looking for what I needed
• No, I did not find what I was looking for

Description

Reservations are currently made with a mongo _id, but should use the users AAdvantage Number.

Expected Behavior

Reservations use mongo _id

Actual Behavior

Reservations use AAdvantage Number

Repro Steps

Look at swagger 🕺 💃

Other Information