message: Refactor UnitController DELETE to use async/await
diff: @@ -185,18 +185,16 @@ export class UnitController {
  */
  @Authorized(['teacher', 'admin'])
  @Delete('/:id')
  - deleteUnit(@Param('id') id: string) {
  - return Unit.findById(id).then((unit) => {
  + async deleteUnit(@Param('id') id: string) {
  + const unit = await Unit.findById(id);
  +
  if (!unit) {
  throw new NotFoundError();
  }
  - return Lecture.updateMany({}, {$pull: {units: id}})
  - .then(() => unit.remove())
  - .then(() => {
  + await Lecture.updateMany({}, {$pull: {units: id}});
  + await unit.remove();
  return {result: true};
  - });
  - });
  }
  protected pushToLecture(lectureId: string, unit: any) {
  