Remove unused SCSS

This breaks the app when rails is upgraded, because `icon-information-transparent.png`
isn't present.
Bump rails to 4.0.9

This picks up the latest 4.0 security fixes.
Merge pull request #78 from alphagov/bump-rails-to-4.0.9

Bump rails to 4.0.9
Prettify EIM00500

This is in preparation to making a small fix to the content.
Expand manual & section viewing specs
Expand manual change note specs