Add supports resource to API

Adds [/api/v1/supports](http://protected-atoll-9623.herokuapp.com/api/v1/supports) to link features with versions.  Builds on PR #5.

Fixes these bugzilla bugs:
* [1063141](https://bugzilla.mozilla.org/show_bug.cgi?id=1063141) - Add feature support by browser version to compat data store
* [1063578](https://bugzilla.mozilla.org/show_bug.cgi?id=1063578) - Expand configuration information in browser-version-features