Three men and two women from the St John's Wood-based Royal Horse Artillery - responsible for representing the Army at the Queen's ceremonial shindigs, lest we forget - have been given the old heave ho after testing positive for Class A drugs during random tests. Though drug use within the Army remains statistically rare, it rose by almost 50 per cent between 2003 and 2007. A spokesperson said: "You cannot be taking drugs and expect......