@dzucconi (cc @dylanfareed): Initial wire up to Spooky

This starts to wire up Positron to Spooky. I've copy & pasted a lot of code from your [Force PR](https://github.com/artsy/force/pull/1272), so thanks for that.

I don't think I know enough about HAL yet to understand how to take advantage of it. Right now it seems like we're just going through the extra effort to override parse to ignore the `_links` and such. Maybe there's a way to write an adapter that better takes advantage of the automatic-crawling/not-hardcoded-urls ideas of HAL. Lemme know if you have any thoughts.

As a side note I've briefly looked at these which may be of use:
https://github.com/mikekelly/backbone.hal
https://github.com/basti1302/traverson
https://github.com/weluse/hyperagent

Still TODO: Write tests for the article/section models, which I will try to loop into my next PR.

![image](https://cloud.githubusercontent.com/assets/555859/4311152/6d0e3042-3eac-11e4-986c-029834e37a2a.png)
If you want to have a purely technical exercise first, try it against Gravity APIv2, and maybe contribute an example or some kind of howto to https://github.com/artsy/doppler (we discuss how to talk to the API in https://developers.artsy.net/start, see "with Ruby").