Add test code #60
Refactor test code #60
Add test code #60
Add baseball.get_champions_of_this_year() #60
Rename 'test_get_champions_before_this_year()' to 'test_get_champions_before_this_year_01()' #60
Add test code #60
Add baseball.get_champions_before_this_year() #60
Add test code #60
Add baseball.get_champions() #60
Merge branch 't0060' close #60