Play: Fix assignment to predicate on robot requirements
Play: Fix assignment to predicate on robot requirements

Two roles would sometimes be assigned to a robot without this fix.
E.g., assignNearestChipper() would return true without erasing a
robot from the set when a 2008 has already been assigned, causing
the next assignment call to assign the 2008 to an additional role.

RoboJackets/robocup-software,JNeiger/robocup-software,RoboJackets/robocup-software,RoboJackets/robocup-software,JNeiger/robocup-software,JNeiger/robocup-software,JNeiger/robocup-software,JNeiger/robocup-software,RoboJackets/robocup-software