UPC and EAN validation checks

We have made improvements to the purchase requirement feature by adding GTIN validation for UPC and EAN check digits. Now, there are two separate data fields for each purchase requirement - one for 12 digit UPCs where TCB will check the validity of the 12th check digit, and the other for 13-digit EANs where TCB will check the validity of the 13th check digit.  This will ensure that TCB is maintaining and exchanging accurate data from the outset of the process.  When sending the purchase requirement data to the retail point-of-sale systems, check digits will be stripped off by default. However, if a retailer utilizes check digits in their platform, they can use a flag called 'include_check_digit' during the redemption flow to let TCB know that removal of the check digit is not required for that particular retailer.