v0.0.8 - Add some methods

Add some methods

• Unix return Unix time as int64
• GetWeekOfMonth returns the week number as int in month by date
• GetDayOfYear return day of year by date
• DateIsPassedInCurrentYear Check for the passed date in the current year
• DateYearsSince Amount of years since the given date
• NthOrLastWeekdayOfMonth Calculate the nth or last weekday of a given month and year.