Typo in the abstract method declariation. I'm not sure how this crept in...

... but certainly not working now whilst trying to implement into a production application. It worked fine yesterday whilst in testing, so I guess I must have accidently typo'd AFTER my initial testing... Yeah I know... WTF right lol! Sorry any chance you can re-tag the 1.1 release as this is breaking ALL gateways as this is GatewayInterface abstract function declaration.