Remove use strict

.babelrc

 {
   "presets": [["es2015", { "loose": true }]],
-  "plugins": ["transform-vue-jsx"],
+  "plugins": ["transform-vue-jsx", "transform-remove-strict-mode"],
   "env": {
     "utils": {
       "plugins": [

package.json

@@ -54,6 +54,7 @@
     "babel-loader": "^6.2.5",
     "babel-plugin-module-resolver": "^2.2.0",
     "babel-plugin-syntax-jsx": "^6.8.0",
+    "babel-plugin-transform-remove-strict-mode": "0.0.2",
     "babel-plugin-transform-vue-jsx": "^3.1.0",
     "babel-preset-es2015": "^6.14.0",
     "chai": "^3.5.0",