Added heuristic interface and implemented 3 heuristics: greedy,
one-neighbor, and two-neighbor. Need to add command line arguments for
which heuristic to use and whether to generate the optimal tree or not.
Added command line argument for heuristic choice. Can be one of greedy,
oneneighbor, or twoneighbor.
Added command line for heuristic and filename.
Updated runTest to take parameter to run optimal generation.
Packaged latest updates into JAR.