Migrate vulcan meteor accounts to vulcan-next

A script that loops through all user created mongo collections, and migrates Meteor _id to a Mongo ObjectId

1. Change the config.js to your database name and mongo connection string
2. Run node start.js to start the migration

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How it works:

• Inserts a new document for every record in order to create the Object ID, then delets the old one.
• Updates all foreign key Meteor IDs of all collections using text search
• Stores the old Meteor ID in document.legacyId field for reference
• The Mongo String ID is used for foreign keys instead of the ObjectID because graphQL queries with filters _and, _or operators only work with the String Id in vulcan-next (unless it's the primary _id)

User migration:

• A user.salt and user.hash will be made from meteor bcrypt password

You can also add your own migrations specific to your app to /migrations folder, and import them to the start.js script - there are a couple examples in there to copy.