pos/pos_meal_voucher/readme/ROADMAP.rst

* Introduce the Meal Voucher Issuer model
* When scaning Meal Voucher, deduce the Issuer
* Add a reporting to make easily the deposit of Meal Vouchers, per issuers.
* Add an option to add subtotal of products that can be paid with meal vouchers,
  on the bill.
* Prevent to scan twice the same Meal Voucher barcode.