Upgrade to Vue Version 4

babel.config.js

@@ -1,5 +1,5 @@
 module.exports = {
   presets: [
-    '@vue/app'
+    '@vue/cli-plugin-babel/preset'
   ]
 }

package.json

@@ -46,6 +46,7 @@
     "axios": "0.18.1",
     "clipboard": "2.0.4",
     "codemirror": "5.45.0",
+    "core-js": "^3.6.4",
     "driver.js": "0.9.5",
     "dropzone": "5.5.1",
     "echarts": "4.2.1",
@@ -74,10 +75,10 @@
   "devDependencies": {
     "@babel/core": "7.0.0",
     "@babel/register": "7.0.0",
-    "@vue/cli-plugin-babel": "3.5.3",
-    "@vue/cli-plugin-eslint": "^3.9.1",
-    "@vue/cli-plugin-unit-jest": "3.5.3",
-    "@vue/cli-service": "3.5.3",
+    "@vue/cli-plugin-babel": "^4.2.3",
+    "@vue/cli-plugin-eslint": "^4.2.3",
+    "@vue/cli-plugin-unit-jest": "^4.2.3",
+    "@vue/cli-service": "^4.2.3",
     "@vue/test-utils": "1.0.0-beta.29",
     "autoprefixer": "^9.5.1",
     "babel-core": "7.0.0-bridge.0",