Initialize Board class
Add seed_bombs method to Board class and add attributes to Tile class
Add #update_display to Board class. Gave Tile class state property.
Create #game_lost? and #game_over?
Create Minesweeper#game_won?
Create Minesweeper#get_user_input
Start work on Minesweeper#run
Make Board#neighbor_bomb_count and helper method #neighbors.
Update Board#neighbors to output array of coordinate pairs
Finish Minesweeper game.