Chore: improve build script

Author: mysticatea

package.json

@@ -18,7 +18,7 @@
     "cpx": "^1.5.0",
     "cross-env": "^5.1.1",
     "css-loader": "^0.28.7",
-    "eslint": "^4.12.0",
+    "eslint": "^4.12.1",
     "eslint-config-mysticatea": "^12.0.0",
     "eslint-plugin-vue": "^4.0.0-beta.0",
     "file-loader": "^1.1.5",
@@ -38,6 +38,7 @@
   },
   "scripts": {
     "build": "cross-env NODE_ENV=production run-s clean build:* -s",
+    "build:update-deps": "npm install eslint@latest eslint-plugin-vue@next vue-eslint-parser@experimental",
     "build:html": "appcache-manifest-fixer src/index.html -o dist/index.html",
     "build:js": "webpack --progress --hide-modules",
     "build:monaco": "node scripts/copy-monaco",