Renamed the original exercise files to be aligned with the Cell domain concept.
Added 4 intention TODOs.
Wrote intention Assert of test Any_live_cell_with_fewer_than_two_live_neighbours_dies.
Finished intention Act and Arrange of test Any_live_cell_with_fewer_than_two_live_neighbours_dies.
Fixed Error: Declared class LiveCell.
Fixed Error: Declared class CellTransitioner.
Fixed Error: Declared class Cell.
Fixed Error: Declared method CellTransitioner::transition().
Fixed Error: Declared that the class LiveCell was the subclass of class Cell.
Fixed Error: Made method CellTransitioner.transition() public.
Fixed Error: Declared the type of the return value of method CellTransitioner.transition().
Fixed Error: Declared class DeadCell.
Fixed Error: Defined method CellTransitioner::transition().
Fixed Error: Included Cell.h in file CellTransitioner.h.
Fixed Error: Returned nullptr in method CellTransitioner::transition().
Fixed Error: Implemented method CellTransitioner::transition().
Updated the intention Assert, Act and Arrange using enum CellState instead of class Cell.
Fixed Errors: Made all production code aligned with the test code.
Finished TODO: Any live cell with fewer than two live neighbours dies.
Renamed test file to be CellTransitioner.tests.cpp.