More cleanup to SASS (SCSS)
-> Styling 'all listings'
-> Added image URL to form / listing_params / listing attributes
Merge branch 'listings' of github.com:felguerez/top-secret-final-project into listings

Conflicts:
	web/app/controllers/application_controller.rb
	web/app/views/layouts/application.html.erb
	web/app/views/listings/index.html.erb
	web/app/views/listings/show.html.erb