Make 12th test green - introduce the awesome if-loop
13th test - handle spare
Make 13th test green with simplest possible return value
13th test, renaming
14th test- calculate difference between 1st pin and 2nd pin to 10 if a spare is thrown
Another baby step to make the 14th test green
Renaming test 14
15th test- calculate difference between to two pins with another values
make 15th test green - now it can haz spare
16th test is green already :) spare in the 2nd frame
17th test - add first pin after a spare to the result
Make 17th green with a hardcoded return value
18th test- check adding of pin2 to the previous frame result if a spare was thrown
make 18th test green - generic handling of spares
19th test - two spares in a game after each other
make 19th test green - bugfixing error in spare handling
20th test - handle misses