Add a more complete package.json

Add a more complete package.json file. The only thing I added that is of note is the license. Up to you on whether that should be there or not. 

You also may want to consider adding an entry point in case this will ever be a project/module that is required. Since you are only using gulp for test/build that is still open to the implementor. I didn't add these since it doesn't make sense the way it is.

```
  "main" : "./index.js",
  "bin"  : "./bin/index.js",
```