Add bancontact as a payment method

What is the need / problem ?

In Belgium, most payments are made with Bancontact.

Who does it impact ?

Buyers

What is the current impact of the problem ?

It limits Open Food to be fully integrated in Belgium

Potential solutions that will solve the problem ?

A. Go through Stripe : t-shirt size L (around 40 hours)
B. Use a new payment method gateway : t-shirt size XL (around 80 hours)

Previous spikes: SPIKE: Bancontact payment method and new French payment method