test on add_workdays for more than a year (spanned over 2 years). closes #4
test on add_workdays for more than a year (spanned over 2 years). closes #4

novafloss/workalendar,novapost/workalendar,shinriyo/workalendar,sayoun/workalendar,jaraco/calendra,ChrisStevens/workalendar,gregn610/workalendar,sirk390/workalendar