install moment.js

package.json

@@ -16,6 +16,7 @@
     "element-ui": "2.0.5",
     "js-cookie": "2.2.0",
     "lodash": "^4.17.4",
+    "moment": "^2.19.4",
     "normalize.css": "7.0.0",
     "nprogress": "0.2.0",
     "vue": "2.5.9",