'Remove a GroupTombstone
Undiscards a group such that new events in that group will be captured.
This does not restore any previous data.
:pparam string organization_slug: the slug of the organization.
:pparam string project_slug: the slug of the project to which this tombstone belongs.
:pparam string tombstone_id: the ID of the tombstone to remove.
:auth: required'

def delete(self, request, project, tombstone_id):

    try:
        tombstone = GroupTombstone.objects.get(project_id=project.id, id=tombstone_id)
    except GroupTombstone.DoesNotExist:
        raise ResourceDoesNotExist
    GroupHash.objects.filter(project_id=project.id, group_tombstone_id=tombstone_id).update(group_tombstone_id=None)
    tombstone.delete()
    return Response(status=204)
