upgrade vue-cli from 3 to 4

babel.config.js

@@ -1,3 +1,3 @@
 module.exports = {
-  presets: ["@vue/app"],
+  presets: ["@vue/cli-plugin-babel/preset"],
 };

package.json

@@ -1,26 +1,26 @@
 {
   "name": "vue-starter",
-  "version": "0.4.0-dev",
+  "version": "0.5.0-dev",
   "private": true,
   "scripts": {
     "serve": "vue-cli-service serve",
     "build": "vue-cli-service build",
+    "test:unit": "vue-cli-service test:unit",
     "lint": "vue-cli-service lint",
-    "start": "vue-cli-service serve",
-    "mock": "json-server --watch mock/db.json",
-    "prebuild:staging": "node prebuild",
-    "build:staging": "NODE_ENV=production vue-cli-service build --mode staging",
-    "prebuild:prod": "node prebuild",
     "build:prod": "vue-cli-service build",
+    "build:staging": "NODE_ENV=production vue-cli-service build --mode staging",
+    "mock": "json-server --watch mock/db.json",
     "postbuild:prod": "node postbuild",
-    "test:unit": "vue-cli-service test:unit"
+    "prebuild:prod": "node prebuild",
+    "prebuild:staging": "node prebuild",
+    "start": "vue-cli-service serve"
   },
   "dependencies": {
     "axios": "^0.18.0",
     "axios-progress-bar": "^1.2.0",
     "bootstrap": "^4.3.1",
-    "core-js": "^2.6.9",
-    "element-ui": "^2.8.2",
+    "core-js": "^3.3.2",
+    "element-ui": "^2.12.0",
     "js-cookie": "^2.2.0",
     "lodash-es": "^4.17.11",
     "moment": "^2.24.0",
@@ -33,22 +33,24 @@
     "vuex-persistedstate": "^2.5.4"
   },
   "devDependencies": {
-    "@vue/cli-plugin-babel": "^3.8.0",
-    "@vue/cli-plugin-eslint": "^3.8.0",
-    "@vue/cli-plugin-pwa": "^3.8.0",
-    "@vue/cli-plugin-unit-jest": "^3.8.0",
-    "@vue/cli-service": "^3.8.0",
-    "@vue/eslint-config-prettier": "^4.0.1",
+    "@vue/cli-plugin-babel": "^4.0.5",
+    "@vue/cli-plugin-eslint": "^4.0.5",
+    "@vue/cli-plugin-pwa": "^4.0.5",
+    "@vue/cli-plugin-unit-jest": "^4.0.5",
+    "@vue/cli-service": "^4.0.5",
+    "@vue/eslint-config-prettier": "5",
     "@vue/test-utils": "^1.0.0-beta.29",
     "babel-core": "7.0.0-bridge.0",
     "babel-eslint": "^10.0.1",
     "babel-jest": "^24.7.1",
     "babel-plugin-import": "^1.11.2",
-    "eslint": "^5.16.0",
+    "eslint": "5",
+    "eslint-plugin-prettier": "^3.1.1",
     "eslint-plugin-vue": "^5.2.2",
     "lint-staged": "^8.1.5",
     "node-sass": "^4.12.0",
-    "sass-loader": "^7.0.1",
+    "prettier": "^1.18.2",
+    "sass-loader": "^8.0.0",
     "vue-cli-plugin-axios": "0.0.4",
     "vue-cli-plugin-element": "^1.0.1",
     "vue-template-compiler": "^2.6.10"