Write test for create_cells method. Make sure it fails when create_cells commented out, passes otherwise
Write test for populate method
Add test to population method test to make sure cell's h and w are correctly assigned
Write test for generation method
Write test for generate_screen method
Refactor create_cells and populate methods into one smaller method
Write tests for find_neighbors method
Write another test for generation method. This test does not pass and that is the problem
Add method to make a shallow copy of a cell. Now one generation works