added test case for a perfect game
Made test case for perfect game pass
Added test case for the end of the throws array
changed tests to have a similar name as the ones from the book
Added test case for a sample game
Added test case for 11 strikes and a 9
added test case for 9 strikes and a spare on the last frame
Changed @first_throw to @first_throw_in_frame
Changed Game#score_for_frame to use another function to handle the score for cases where a second throw is needed
Updated Game#score_for_frame to increment the ball ivar after every throw