Run All Tests

By default minitest isn't running all files in our suite. 

    test/unit/smartdown_content/smartdown_scenarios_test.rb

Was not run. This lead to https://github.com/alphagov/smart-answers/commit/0dcdc8e242eb335ce399010fcd09a9bbeb4fc06d not being picked up.

I have manually loaded all the files using Rakes FileList