Loads of PR improvements

* README
    * Updated parallelLimit description
    * Removed tests / travis TODO
* Markets
    * Removed the wrapper object for the list of markets
    * From double quotes to single quotes
* `Search.coffee`
    * `useGzip` option for the Search constructor
    * formatting
    * Removed userAgent
    * Added PAGE_SIZE to replace `50` littered throughout
    * Replace `_.defaults` in `parallelSearch`
* `package.json`
    * Updated `main` to point to `lib/search.js`
    * Updated `test`
* `.travis.yml`
    * Removed `before_script`
* `Gruntfile.coffee`
    * Added lots of coffeelint options