Adds sass-embedded as possible sass-loader backend (see #1093)

Author: leonexcc

lib/features.js

@@ -21,7 +21,7 @@ const features = {
         packages: [
             { name: 'sass-loader', enforce_version: true },
             // allow node-sass or sass to be installed
-            [{ name: 'sass' }, { name: 'node-sass' }]
+            [{ name: 'sass' }, { name: 'sass-embedded' }, { name: 'node-sass' }]
         ],
         description: 'load Sass files'
     },