Pull FAQs from API

- [x] Add fixture
- [ ] Add HTTP request
- [ ] Parse response for building Topics state
- [ ] Parse response for building Questions state
- [ ] Parse response for building Answer state


API docs: https://github.com/BeSnappy/api-docs

Should use a [PaginatedChoiceState](http://vumi-jssandbox-toolkit.readthedocs.org/en/release-0.2.x/states/reference.html#PaginatedChoiceState) to list topics and questions. Should use a [BookletState](http://vumi-jssandbox-toolkit.readthedocs.org/en/release-0.2.x/states/reference.html#BookletState) to show content.
please move all the configurable elements (username, base of the api) to the config (mock it at the top of the tester too)