chore(e2e): upgrade vue-cli

tests/demo/babel.config.js

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

tests/demo/package.json

@@ -8,13 +8,14 @@
     "lint": "vue-cli-service lint",
     "apollo:dev": "vue-cli-service apollo:dev",
     "apollo:start": "vue-cli-service apollo:start --port 4042",
-    "test:e2e:dev": "start-server-and-test apollo:dev http://localhost:4042/.well-known/apollo/server-health test:e2e:dev:client",
-    "test:e2e:dev:client": "vue-cli-service test:e2e --mode development",
+    "test": "yarn run lint --no-fix && yarn run test:e2e",
     "test:e2e": "start-server-and-test apollo:start http://localhost:4042/.well-known/apollo/server-health test:e2e:client",
     "test:e2e:client": "vue-cli-service test:e2e --mode production --headless",
-    "test": "yarn run lint --no-fix && yarn run test:e2e"
+    "test:e2e:dev": "start-server-and-test apollo:dev http://localhost:4042/.well-known/apollo/server-health test:e2e:dev:client",
+    "test:e2e:dev:client": "vue-cli-service test:e2e --mode development"
   },
   "dependencies": {
+    "core-js": "^3.1.2",
     "graphql-type-json": "^0.3.0",
     "marked": "^0.7.0",
     "shortid": "^2.2.8",
@@ -23,12 +24,14 @@
     "vuex": "^3.0.1"
   },
   "devDependencies": {
-    "@vue/cli-plugin-babel": "^3.12.0",
-    "@vue/cli-plugin-e2e-cypress": "^3.12.0",
-    "@vue/cli-plugin-eslint": "^3.12.0",
-    "@vue/cli-service": "^3.12.0",
+    "@vue/cli-plugin-babel": "^4.0.4",
+    "@vue/cli-plugin-e2e-cypress": "^4.0.4",
+    "@vue/cli-plugin-eslint": "^4.0.4",
+    "@vue/cli-service": "^4.0.4",
     "@vue/eslint-config-standard": "^4.0.0",
+    "eslint": "^4.19.1",
     "eslint-plugin-graphql": "^3.1.0",
+    "eslint-plugin-vue": "^5.2.3",
     "graphql-tag": "^2.5.0",
     "start-server-and-test": "^1.10.6",
     "stylus": "^0.54.5",