DUNCAN MIRIRI KENYAN digital payments company Cellulant plans to shift its focus to small and medium enterprises with the aim of turbo-charging its merchant acquisition growth to 50,000 this year from the current rate of about 1,000, its chief executive told Reuters. Investors have been flocking into African financial technology firms due to rapid growth in services like cash transfers between bank accounts and mobile phone wallets. read more Cellulant, which has previously raised funds from investors like Velocity Capital and TPG's Rise Fund, is in the middle of a $100 million Series D fundraising round, partly to finance the shift…