Add script to migrate existing MongoDB contents
We need to transfer the existing data of the old VILLASweb instance to the new one. That means transferring data from MongoDB + old data model to ProstreSQL DB + new data model. Details about the data model are discussed in this issue: #15 (closed)
Our idea (see discussion below) is to use the old and new APIs and implement a script that does the migration automatically. This will be a good test for the new API.