Add the initial model for a simple smart answer edition
Store a hash of nodes, not the "flow"

The flow was just a wrapper around a collection of
nodes, along with the title and body - which we're
going to store in the artefact/edition.
Validate that all nodes are hashes and have titles
Make sure the factory actually has valid nodes :-)
Add test to assert node order
Merge remote-tracking branch 'origin/add-simple-smart-answer-model'