Changing simplified-expenses-checker v2 files into v1

This is due to be published 12th August
Updating state-pension-through-partner v2 to v1
Merge pull request #1056 from alphagov/publish_simplified_expenses_checker

Updating simplified-expenses-checker smart-answer
Merge pull request #1057 from alphagov/publish_state_pension_through_partner

Updating state-pension-through-partner smart-answer
Smartdown in smart answers application
Use Ruby enumerables for body and devolved_body
Documentation for both styles of smart answers

Smartdown in smart answers application

Documentation for both styles of smart answers
Draft and version status, upgrade smartdown to 0.0.4