Projects (will eventually contain multiple todos)

The goal of this request is to add a model that can pull its information from a JSON API (in this case, literally using the [JSON API](http://jsonapi.org/) format).

For testing purposes the requests are being mocked using Sinon's [FakeServer](http://sinonjs.org/docs/#fakeServer). This may also be useful during development to remove the need for a server-based API.

Todos:

- [x] Add has-many relationship to todos.
- [ ] Consider an identity map or similar approach
- [x] Build simple UI
- [x] Investigate/create development API to tie to UI
- [ ] Introduce [SyncMachine](http://docs.chaplinjs.org/chaplin.sync_machine.html)
- [x] Extract shared model/collection functionality to trabian-webapp-core

cc: @trabian/client-side