Start to use JSON files as mock API responses

I wrote a few little ruby scripts to generate mock JSON API responses so we don't have to do that heavy XML parsing every time we refresh the browser. I committed a few of them to the API folder, check out the new `loadData` function in `js/data.js`

I created the [mock_API](https://github.com/data-visualization-capstone/mock_API) repo for the ruby scripts I used to create this. I'm happy to move these back to JS, but I just wanted to get something done quickly and I was having trouble wrapping my head around node async file operations...