How do I update ember.js to version 2.0.1

I'm fairly new to ember.js

Before starting my project I wanted to upgrade my version to the latest 2.0.1 release.

I went through the steps in the guide.

sudo npm uninstall -g ember-cli
sudo npm cache clean
bower cache clean
sudo npm install -g ember-cli

typing: ember -v gives 1.13.8 just as it did before the 'update'

I can see that the ember-cli website says 1.13.8 is the latest version of ember-cli.
However since the emberjs.com site says the latest release is 2.0.1 and on the homepage the isntruction is to run npm install -g ember-cli I would expect the command
ember -v to return 2.0.1 if I was using the latest release.

I created a new ember project using ember new test and ran
grep -r 'version' * to see if there were any clues but found nothing of interest.
Looking at package.json reveals that ember-data 1.13.8 is one of the dependencies which is also not the latest version (2.0.0)

• What (if any) is the difference between ember-cli and ember.js versions?
• When I type ember -v the version of which program is being displayed?
• If I'm not on the latest release, how can I get it installed?

I'm running ubuntu 14.04