Allow loading scenario data into form
Fix bug in JS form initialization

In the absence of form_data being submitted to the page (which is not available when using scenario data), the form would not be initialised with the correct state (resulting in the wrong sections being open).
Only allow scenario loading on !production envs
Handle case where journey not available
Allow journey data to be reloaded from spreadsheet
Fix an inconsistency in Yes/No capitalisation

* This fixes the loading of the ‘defendant inhabits property’ field from scenarios
* In other places the internal representation is Yes/No - this was inconsistent
Added missing notice_served field to scenario data

This again fixes an issues loading scenario data
Change assured/demoted capitalisation in scenarios

This again corrects an inconsistency between the two representations.

It might have been better to go with the capitalised version, but this would have required more code changes, and this particular string is not used elsewhere.
Moved fixture classes into app/lib - used at runtime
Include curb in runtime requirements

Also remove pry which we don’t want to load in prod
Replace curb with excon

Curb wasn’t building on servers so let’s use something without native extensions.
Merge pull request #452 from ministryofjustice/allow_loading_fixture_data

Allow loading fixture data