添加 node-sass依赖

package.json

@@ -16,6 +16,7 @@
     "font-awesome": "^4.7.0",
     "http-proxy-middleware": "^0.17.4",
     "jsonp": "^0.2.1",
+    "node-sass": "^4.5.3",
     "nuxt": "0.10.6",
     "vue-awesome-swiper": "^2.5.4",
     "vue2-filters": "^0.1.9"