Red- Added a test for check the return of the new generation of the grid
Green- nextGeneration returns the new grid
Refactor- Inline of the original grid and removing test.
Red- nextGeneration must return a grid
Green- Make nextGeneration method return a grid
Refactor- Deleted unused test and inlined the result of the nextGeneration
Red- Added a test that verify that the size of the new grid is the same as the original
Green- nextGeneration returns a grid with the same size
Refactor- Deleted unused test and extracted the parameter for nextGeneration method
Red- test added to verify that one live cell without neighbors must die
Green- kill live cell without neighbors
Refactor- Deleted unused test and extraction of method for clarity
Red- added a test to verify that next generation of one live cell with two neighbors must live
Green- now if a live cell has two neighbors is continue live in the next generation
Refactor 1- first refactor, extracting methods to make the code more readable
Merge remote-tracking branch 'origin/master'