Chore/update mongodb package

[adieuadieu]

Updates the mongodb npm package to it's latest version.

Some small changes were made to Mongorito's code. Specifically:

• MongoClient.connect() was deprecated, now using new MongoClient().connect()
• MongoClient.collections no longer exists. You have to create a db instance with MongoClient.db() on which the collections() function now exists.

While none of the Mongorito APIs or methods have changes, the update to mongobd@3 package may result in breaking changes if someone used Mongorito with use of private/undocumented Mongorito properties (e.g. mongorito's database._connection property). Therefore might make sense to release this (in conjunction with #205) as a major version release, just in case.

/cc @vadimdemedes 😄

[jamescorbett]

This pull request is great, and I agree with the major version change. I was using the undocumented _connection for example.

Please can you bump the version further to "mongodb": "^3.1.2" because of a bug in mongodb's driver. See https://github.com/meteor/meteor/issues/9944#issuecomment-420542042 for detail, although it's regarding Meteor, I've run into the same issue on Mongorito.