Added basic header design
new file:   app/assets/images/dark-background.jpg
modified:   app/assets/stylesheets/application.css
modified:   app/assets/stylesheets/main.scss
new file:   app/assets/stylesheets/nav.scss
new file:   app/assets/stylesheets/search.scss
new file:   app/assets/stylesheets/variables.scss
modified:   app/views/layouts/_nav.html.erb
Added basic design for search
modified:   app/views/activities/_search_form.html.erb
modified:   app/views/activities/_when_search.html.erb

Moved the SLug into a library
modified:   app/assets/stylesheets/search.scss

new file:   app/assets/images/back-test.jpg
new file:   app/assets/images/nav.jpg
modified:   app/controllers/activities_controller.rb
modified:   app/models/activity.rb
modified:   app/models/category.rb
renamed:    app/models/category.rb -> lib/slug_mapping.rb