prints out a one line command to update dependencies

added a command that you can copy and paste to update deps

```
Outdated Dependencies

optimist (package: 0.3.4, latest: 0.3.5)
js-yaml (package: 1.0.2, latest: 2.0.3)
marked (package: 0.2.5, latest: 0.2.8)

npm install --save optimist@0.3.5 js-yaml@2.0.3 marked@0.2.8


Outdated Dev Dependencies

mocha (package: 1.6.0, latest: 1.8.2)
grunt (package: 0.3.17, latest: 0.4.1)
grunt-simple-mocha (package: 0.2.0, latest: 0.3.2)

npm install --save-dev mocha@1.8.2 grunt@0.4.1 grunt-simple-mocha@0.3.2
```