Check that department restrictions on stocktype ABV are still working

[sde1000]

Somehow a member of staff at the Dev was able to create a stocktype in the Real Ale department (minimum ABV 0.6%) with null ABV on the till while working on a delivery.

[sde1000]

It's possible this is before the ABV restrictions were put in place, in February — see the log entries for precise order of events.