A5: add tests for redundant solvers
A5: add tests for redundant solvers

that is, make clear what we want to see when the initial and goal states
given to a PuzzleSolver() are the same.

rfdickerson/CS241,rfdickerson/cs241-data-structures,rfdickerson/cs241-data-structures,rfdickerson/CS241,rfdickerson/cs241-data-structures,rfdickerson/CS241