Pump test

I set up a basic pump test to test any formula/logic used to calculate
the amount of fluid dispensed from a pump.
New pumping logic and preventing races

Implemented logic to prevent a potential race condition with the drink
queue size variable.  I also set up the pumping logic to turn on all the
pumps that still have remaining volume at the same time.  Also the
interupt is set up to go off with a frequency in line with with flow rate
of the pump.  So each call to the interupt represents 1mL of fluid.