Support async migration

[megawebmaster]

There is a better way to support async migrations:

Migrations.add({
  version: 1,
  up: Meteor.wrapAsync(async (_, next) => {
    await doSomethingAsynchonously();
    next();
  }),
  down: Meteor.wrapAsync(async (_, next) => {
    await doDownAsynchronously();
    next();
  }),
});

Current implementation supports it as the solution uses built-in Meteor behavior from Fibers :muscle: I hope it helps someone.

[StorytellerCZ]

I'm closing this as there is a workaround provided by @megawebmaster and impending upgrade for Meteor 3.