test: eslint webpack as well

package.json

@@ -8,7 +8,7 @@
     "start": "npm run dev",
     "build": "cross-env NODE_ENV=production webpack --config webpack/prod.config.js --progress --display-error-details --colors",
     "dev": "cross-env NODE_ENV=development webpack-dev-server --config webpack/dev.config.js --watch --colors",
-    "test": "eslint src"
+    "test": "eslint src webpack"
   },
   "files": [
     "dist"