Merge 980af60dcaf6bc7bceaa8d49d1a1dec5e630274f into 26dcc61e108f70d71d98c4a973dd61e269d3b590
add exceptional case on -(NSInteger)year
add test for -(NSInteger)gregorianYear
Merge branch '8/merge'

close #8
bump 1.2.1
gregorianYearの算出方法にバグが有ったので修正