disable submitting form with closed status but no closed_on date
Only show close date if status == closed
Revert "disable submitting form with closed status but no closed_on date"

This reverts commit 10fe359efaed2134659070fd1f85472f8261fd25.
correct validation using ng-required
Merge pull request #94 from alindeman/hide_validate_closed_at

disable submitting form with closed status but no closed_on date