Merge pull request #110 from alphagov/remove-unused-code

Remove unused code as reported by SimpleCov
Change notes for manual sections
Merge pull request #112 from alphagov/change-notes

Change notes for manual sections
Manual must publish its documents everytime
Merge pull request #113 from alphagov/fix-add-section-after-initial-publish

Manual must publish its documents everytime
Use govuk_admin_template

- Add gem to gemfile
- Include stylesheet in base.css
- Rewrite application.html.erb to use template