Make 20th test  green- now can handle a miss
21st test- handle a miss in 1st pin
make 21st test green - handle a miss in 1st pin
22nd test - two misses - already green
23rd test - throw an error if there are too many frames
23rd test - fixed number of frames
Make 23rd test green
24th test- play ten frames without an error
25th test- play eleven frames should throw an error
26th test- eleven frames if the 10th frame was a strike
make 26th test green - eleven frames if the 10th frame was a strike
27th test - no more than 11 frames, even if the last throw was a strike