Cumulative updates - new features bundle

I'm sorry but the other PR's quickly became a mess. I'm collecting all of them in this PR and making sure it passes travis-ci.

1) Update dependencies
2) Support writing output to multiple files, with different JSON data
```javascript
faker: {
	slideDeck: {
		options: {
			jsonFormat: '<%= yeoman.app %>/data/slideDeck.faker.v1.js',
			out: ['<%= yeoman.app %>/data/slideDeck1.json', '<%= yeoman.app %>/data/slideDeck2.json']
		}
	}
}
```
3) When faking data you might want to do some pre/postfixing.
E.g: `"id": "sd{{Helpers.randomNumber(100)}}",` or `"id": "{{Helpers.randomNumber(1)}}0",` will output
`"id": "sd38",` or `"id": "50",`