add version report

Output right now looks like this:

```
Svarog:npm smikes$ ./cli.js doctor
The doctor is in.
 node version: v0.10.33
 npm version : 2.1.8
 -> upgrade your npm to the latest version, 2.1.9
    $ sudo npm -g install npm
    https://github.com/npm/npm/wiki/Troubleshooting#try-the-latest-stable-version-of-npm

```

Comments, @faiq or @othiym23