Deletes the box specified by the key
		Args:
			returns 	(status code for the DELETE request, success message dict)

def delete_box(self, key):
		'''Deletes the box specified by the key
		Args:
			returns 	(status code for the DELETE request, success message dict)
		'''
		if key:
			uri = self.box_root_uri + '/' + key
			return self._req('delete', uri)
		else:
			return requests.codes.bad_request, None