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

test/helpers/sleep.js

@@ -1,7 +1 @@
-export async function sleep (seconds = 1) {
-  let milliseconds = seconds * 1000;
-
-  return new Promise((resolve) => {
-    setTimeout(resolve, milliseconds);
-  });
-}
+export { default as sleep } from '../../website/server/libs/sleep';