old_contents: const mongodb = require('mongodb');
  const uri = process.env.MONGODB_URI;
  
  mongodb.MongoClient.connect(uri, function(err, client) {
      if (err) throw err;
  });
new_contents: const mongodb = require('mongodb');
  const uri = process.env.MONGODB_URI;
  const dbName = process.env.DB_NAME;
  
  const seedData = [
      {
          type: 'HQ unit',
          name: 'Officer',
          cost: [ {name: 'Second Lieutentant', regular: 50, veteran: 65}, 
                  {name: 'First Lieutentant', regular: 75, veteran: 90} ],
          team: '1 officer and up to 2 additional men',
          weapons: [ 'pistol', 'submachine gun', 'rifle', 'assault rifle' ],
          options: [ {name: 'Bodyguard', regular: 10, veteran: 13} ]
      }
  ];
  
  mongodb.MongoClient.connect(uri, (err, client) => {
      if (err) throw err;
  
      let db = client.db(dbName);
      let army = db.collection('army');
  
      // TODO setup migration for db
      // army.insert(seedData, (err, result) => {
      //     if (err) throw err;
      // });
  });
subject: Create insert statement