Sweden was predicted to become entirely cashless by 2030.As the country developed its own mobile payment system, called Swish, banks slowly stopped handling cash, and tills disappeared from shops.With cash circulation the lowest as a share of GDP in the world, Swedish progress was lauded, and observers wondered how it had forged so far ahead of the rest of Europe so quickly.A sign on a store advertises it as a cash-free establishment, and thanks customers for paying by card or by Swish - Belinda...