update node-sass dependency

client/package.json

@@ -59,7 +59,7 @@
         "karma-webpack": "3.0.5",
         "moment": "2.21.0",
         "ngtemplate-loader": "2.0.1",
-        "node-sass": "4.13.0",
+        "node-sass": ">=4.13.1",
         "phantomjs": "2.1.7",
         "phantomjs-prebuilt": "2.1.16",
         "postcss-loader": "2.1.1",