Tested calculateProduction() and worked out bugs.  Wrote tester class.
Merge branch 'master' of https://github.com/msnorth/cs2340_mule.git

Conflicts:
	edu/gatech/cs2340/engine/Round.java
	edu/gatech/cs2340/test/ProductionTester.java
Merge branch 'master' of https://github.com/msnorth/cs2340_mule.git
Fixed bug so now ResourceAmount only increments for the kind of MULE
placed on the tile.
Edited tester, but since Store and other classes are so intertwined with
the GUI, I abandoned this effort.
Production calculation only happens for the particular type of MULE (if
any) on a Tile.