Add some failing tests around BusinessHours#after when using work_hours
BusinessHours#after should respect work_hours

BusinessHours#after was using the private method off_hours to jump ahead
to to the next days beginning_of_day, but that method did not check for
day-specific work hours.
Merge pull request #49 from covermymeds/business-hours-should-respect-work-hours

Business hours should respect work hours