Feature/simple api

Uses the `locals: {...}` hash to ensure that the exact same data sent to our views also gets rendered as json.

If, for example, you visit `/articles/article-type/quick-answer.json`, you'll get (prettified):

```javascript
{
  "article_type": "QuickAnswer",
  "articles": [
    {
      "id": 2,
      "updated": null,
      "title": "How do I renew my driver license?",
      "content": "<div class=\"quick_top\"><h2>Renew your license in person at a <a target=\"_blank\" href=\"http:\/\/hnlanswers.herokuapp.com\/articles\/3\/\">driver license station or Satellite City Hall<\/a>.<\/h2>\r\n<p>Requirements at the station:\r\n<ol><li>Bring your current license.<\/li>\r\n<li>Bring your <a href=\"http:\/\/hawaii.gov\/dot\/hawaiis-legal-presence-law\" target=\"_blank\" >proof of legal presence.<\/a><\/li>\r\n<li>Fill out an application form.<\/li>\r\n<li>Take an eye test.<\/li>\r\n<li>Pay with personal check or cash.<\/li>\r\n<\/ol><\/div>\r\n<div class=\"quick_bottom\"><h3>what you need to know<\/h3>\r\n<p>Driver license fees depend on the duration of the license you are applying for.<\/p>\r\n<table>\r\n<tr>\r\n<th>Two-Year License<\/th>\r\n<th>Four-Year License<\/th>\r\n<th>Eight-Year License<\/th>\r\n<\/tr>\r\n<tr>\r\n<td>$10.00<\/td>\r\n<td>$20.00<\/td>\r\n<td>$40.00<\/td>\r\n<\/tr>\r\n<\/table>\r\n<p>If your license has been expired for more than 90 days, you will be charged an additional reactivation fee of $5 for every 30-day period beyond the 90 days.<\/p><\/div>",
      "created_at": "2014-06-24T20:19:27.579Z",
      "updated_at": "2014-06-24T20:19:27.579Z",
      "content_type": null,
      "preview": "Go to a driver license station with your proof of legal presence and current license, fill an application form there, take eye test, and pay fees.",
      "contact_id": 1,
      "tags": "renew driver license, renew drivers license, renew driver's license, renew license, renew driving license, extend driver license, extend drivers license, extend driver's license, extend license, extend driving license, renewal ",
      "service_url": null,
      "slug": "how-do-i-renew-my-driver-license",
      "category_id": 1,
      "access_count": 0,
      "author_pic_file_name": null,
      "author_pic_content_type": null,
      "author_pic_file_size": null,
      "author_pic_updated_at": null,
      "author_name": null,
      "author_link": null,
      "content_md": null,
      "render_markdown": true,
      "content_main": null,
      "content_main_extra": null,
      "content_need_to_know": null,
      "status": "Published",
      "user_id": null,
      "title_es": null,
      "preview_es": null,
      "content_main_es": null,
      "title_cn": null,
      "preview_cn": null,
      "content_main_cn": null
    }
  ]
}
```