chore(build): ESLint should also lint .vue files (#68)

Author: jedrzejchalubek

.eslintrc

@@ -1,4 +1,7 @@
 {
+  "extends": [
+    "plugin:vue/essential"
+  ],
   "rules": {
     "indent": ["error", 2]
   },

package.json

@@ -6,7 +6,7 @@
     "prod": "npm run production",
     "production": "cross-env NODE_ENV=production webpack --progress --hide-modules --config build/webpack.config.js",
     "watch": "npm run development -- --watch && webpack-dev-server --progress --colors",
-    "lint:js": "eslint resources/assets/js/**/*.{js}",
+    "lint:js": "eslint resources/assets/js/**/*.{js,vue}",
     "lint:sass": "stylelint resources/assets/sass/**/*.{scss,sass}",
     "lint": "npm run lint:js && npm run lint:sass"
   },
@@ -25,6 +25,7 @@
     "dotenv": "^5.0.1",
     "eslint": "^4.10.0",
     "eslint-loader": "^1.9.0",
+    "eslint-plugin-vue": "^4.7.1",
     "extract-text-webpack-plugin": "^3.0.0",
     "file-loader": "^0.11.1",
     "imagemin-webpack-plugin": "^1.4.4",