Make SlotMachine class a Stack middleware #16
Description
At the moment the Symfony request is either injected into the constructor or a new one is created from globals by default. https://github.com/archfizz/slotmachine/blob/master/src/SlotMachine/SlotMachine.php#L66
It would be better to implement HttpKernelInterface and handle the request instead.
This would also make it Stack compliant.