SimpleSmartAnswers landing page.
Test helpers to rin with and without javascript
Integration test for basic path through a smartanswer
Remove business_proposition from smart_answer fixture

For consistency with 7e6fcad
Routing for Smart-Answer flows
Initial model structure to represent a flow.
Controller and view showing current question title.
Add completed_questions to flow state.
Output completed questions and current question form.
Fix smart_answer controller test to work with views
Handle question form submissions
Generate "Change this answer" links
Render outcomes.
Support for changing an answer.
Remove redundant method
Handle invalid answers.
Add question body into view.
Support previewing a draft smart_answer

This involves persisting the edition param through the flow.
Fix stubs in test to match test data
Set cache-control header for simple_smart_answers