fix: Failed to compile (#4)

Author: madplay

package.json

@@ -49,7 +49,8 @@
     "@vue/cli-plugin-babel": "^3.0.5",
     "@vue/cli-plugin-eslint": "^3.0.5",
     "@vue/cli-service": "^3.0.5",
-    "vue-template-compiler": "^2.5.17"
+    "vue-template-compiler": "^2.5.17",
+    "core-js": "^2.6.5"
   },
   "napa": {
     "jquery.flot.animator": "https://github.com/Codicode/flotanimator.git#3c256c0183d713fd3bf41d04417873928eb1a751",