npm install download incompatible MongoClient version

[davidnussio]

This is not a bug but now installing mongodb npm download the 3.0.0-rc0 version.
MongoClient.connect return client instead db.

The code generated with feathers-cli failed with the error:
TypeError: db.collection is not a function

• Fix with downgrade mongodb version to 2.2.x
• Fix follow the example below

const MongoClient = require('mongodb').MongoClient;
const service = require('feathers-mongodb');

MongoClient.connect('mongodb://localhost:27017/feathers').then(client => {
  app.use('/messages', service({
    Model: client.db('feathers').collection('messages')
  }));
  app.use('/messages', service({ Model, id, events, paginate }));
});

[daffl]

If you could update the example that would be great. The latest generator already has been updated in feathersjs-ecosystem/generator-feathers#318.

[daffl]

Closed via #103