message: API: Add DeleteCleanupCache to DownloadController
diff: import {promisify} from 'util';
  import {Response} from 'express';
  import {
  - Body, Post, Get, NotFoundError, ForbiddenError, ContentType, UseBefore, Param, Res, Controller,
  - CurrentUser
  + NotFoundError, ForbiddenError, ContentType, UseBefore, Param, Res, Controller,
  + Body, Post, Get, Delete, CurrentUser, Authorized
  } from 'routing-controllers';
  import passportJwtMiddleware from '../security/passportJwtMiddleware';
  import {Unit, FreeTextUnit, CodeKataUnit, TaskUnit} from '../models/units/Unit';
  @@ -240,4 +240,22 @@ export class DownloadController {
  throw new NotFoundError();
  }
  }
  +
  + /**
  + * @api {delete} /api/download/ Request to clean up the cache.
  + * @apiName DeleteCleanupCache
  + * @apiGroup Download
  + * @apiPermission admin
  + *
  + * @apiSuccess {Object} result Empty object.
  + *
  + * @apiSuccessExample {json} Success-Response:
  + * {}
  + */
  + @Delete('/cleanup/cache') // The extra path separator is here to differentiate the route from the regular /:id requests.
  + @Authorized(['admin'])
  + deleteCleanupCache() {
  + this.cleanupCache();
  + return {};
  + }
  }
  