test: clear cron jobs to make node exit

src/test/common.js

@@ -3,6 +3,7 @@
 const apps = require('../apps.js'),
     appstore = require('../appstore.js'),
     constants = require('../constants.js'),
+    cron = require('../cron.js'),
     dashboard = require('../dashboard.js'),
     database = require('../database.js'),
     domains = require('../domains.js'),
@@ -242,6 +243,7 @@ async function cleanup() {
     nock.cleanAll();
     mailer._mailQueue = [];
 
+    await cron.stopJobs();
     await database._clear();
     await database.uninitialize();
 }