message: update webpack version
diff: "postcss-loader": "1.2.1",
  "react-addons-test-utils": "15.2.1",
  "sass-loader": "4.0.2",
  - "webpack": "2.1.0-beta.25",
  + "webpack": "2.2.0-rc.2",
  "webpack-dev-server": "2.1.0-beta.8",
  "webpack-merge": "2.0.0"
  },
  