fix(pivotal-ui-rails): use 'font-url', not 'asset-url' for font paths

This reverts commit 836594f.

- Previously, we thought that font-url created a compass dependency. It
  does not. 'font-url' is a rails asset pipeline helper

[Fixes #85540054]

Signed-off-by: Geoff Pleiss <gpleiss@pivotal.io>

README.md

@@ -54,14 +54,14 @@ You'll need to maintain the structure in the release directory to have fonts and
 
 If you're installing PivotalUI into a Rails project, you should unzip the constituent files into a directory named `vendor/assets/pui-vX.X.X`.
 
-When linking to the CSS file in your HTML/Sass, link to `pivotal-ui-rails.css` instead of the top-level `pivotal-ui.css`.
+In your `application.scss` file, add the line `@import "pivotal-ui-rails"`
+
+In your `application.js` file, add the line `//= require pivotal-ui` as **the very first** require declaration.
 
 Lastly, in your application's `config/application.rb`, you'll need to add the following to make sure all vendored files are properly compiled:
 
 ```
-    config.assets.paths << Rails.root.join('vendor', 'assets', 'pui-vX.X.X', 'images')
     config.assets.precompile << /\.(?:svg|eot|woff|ttf)\z/
-    config.assets.precompile += %w( pivotal-ui-rails.css pivotal-ui.js )
 ```
 
 # Including SCSS variables (optional, beta)

gulpfile.js

@@ -95,10 +95,10 @@ gulp.task('_compassBuildPui', ['_cleanBuiltPuiScss'], function() {
 gulp.task('_compassBuildPuiRails', ['_cleanBuiltPuiScss', '_compassBuildPui'], function() {
   return gulp.src('build/pivotal-ui.css')
     .pipe(
-      replace(/url\(('|")\.\.\/fonts\//g, 'asset-url\($1fonts\/')
+      replace(/url\(('|")\.\.\/fonts\//g, 'font-url\($1fonts/')
     )
     .pipe(
-      replace(/url\(('|")\.\.\/images\//g, 'image-url\($1')
+      replace(/url\(('|")\.\.\/images\//g, 'image-url\($1images/')
     )
     .pipe(rename('pivotal-ui-rails.css'))
     .pipe(gulp.dest('build/'));