Improve Readme
Test all gutter balls
Fix no score method
Passing test for all gutter balls
Test knocking down 1 pin each roll
Passing test for knocking down 1 pin each roll
Link to ten-pin bowling scoring in readme
Test for rolling a strike
Passing test for rolling a strike and getting a strike bonus
Refactor: Extract is_strike method
Refactor: Extract strike bonus method
Test getting all strikes
Test for getting a spare
Implement getting a spare
Refactor is_spare
refactor spare bonus
Refactor test names
Refactor strike points