Remove campaigns from static

This is going to be moved over to the Frontend application and will be
referenced from the relative view point, e.g.
https://github.com/alphagov/frontend/tree/master/app/assets/stylesheets/views
Remove tour styles from static

This will now live in the Frontend application.
Remove search stylesheet from static and move to Frontend
Merge pull request #251 from alphagov/move-styles-from-static-frontend-views

Remove stylesheets that should be in Frontend