Node 8 (WIP) (#9946)

* start upgrade to node 8

* upgrade travis

* improve travis

* Remove bluebird, babel (except for modules) from server (WIP) (#9947)

* remove bluebird, babel from server (except for modules)

* fixes

* fix path

* fix path

* fix export

* fix export

* fix test

* fix tests

* remove plugin for transform-object-rest-spread since it is supported in node8

* babel: correct syntax rest spread

* remove bluebird

* update migrations archive readme

* fix package-lock.json

* fix typo

* add package-loc

website/server/middlewares/cron.js

@@ -1,6 +1,5 @@
 import moment from 'moment';
 import * as Tasks from '../models/task';
-import Bluebird from 'bluebird';
 import { model as Group } from '../models/group';
 import { model as User } from '../models/user';
 import { recoverCron, cron } from '../libs/cron';
@@ -99,7 +98,7 @@ async function cronAsync (req, res) {
     tasks.forEach(task => {
       if (task.isModified()) toSave.push(task.save());
     });
-    await Bluebird.all(toSave);
+    await Promise.all(toSave);
 
     await Group.processQuestProgress(user, progress);