[Assignments] Assignment Bulk Update: Negative Date Shift

[aaron_bahmer]

Thank you for implementing https://community.canvaslms.com/ideas/2214-adjust-all-assignment-and-quiz-dates-on-a-single-page  and https://community.canvaslms.com/ideas/16898-bulk-update-selectedall-assignments" modifiedtitle="true...!! Amazing!

During the demo provided by a representative today, we saw how easy it was to shift due dates forward by a number of days. I then wondered about moving those dates backwards. It was shown that the field only allowed positive integers.

Since something like spring break/Easter break may move around in either direction, please allow the bulk date shift to allow negative numbers as well.

Thanks!