Refactor Board#place_bombs
Refactor Board#make_tiles
Refactor Tile#mark
Mark Board#make_tiles and Board#place_bombs and #print_row as private
Refactor Board#tile_at_location
Refactor Board#neighbors and Board@valid_neighbor_coords
Move Board#valid_neighbor_coords to private
Move #explore to Tile class.
Rename/move Minesweeper#add_move_to_board to Board#update
Remove old comments.
Simplify Board#update. Will handle flagging in seperate method.
Refactor Minesweeper#get_move
Refactor Minesweeper#won?
Update win/lose conditions.
Streamline Tile#explore
Minor bugfixes.
Mostly working.