include sass-loader as dep

Author: yyx990803

package.json

@@ -1,6 +1,6 @@
 {
   "name": "laravel-elixir-vue-2",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "'Laravel Elixir Vue 2.0 Integration'",
   "main": "index.js",
   "repository": {
@@ -20,6 +20,7 @@
   "dependencies": {
     "css-loader": "^0.23.1",
     "file-loader": "^0.9.0",
+    "sass-loader": "^4.0.0",
     "url-loader": "^0.5.7",
     "vue-loader": "^9.3.2"
   }