“未捕获的错误：部署到heroku时找不到模块” React“”错误

Question

我是新来的反应者，这是我尝试部署到heroku的第一个项目。 这是我的webpack配置：

 module.exports = {
  entry: ['./src/index.js'],
  output: {
    path: __dirname,
    publicPath: '/',
    filename: 'bundle.js'
  },
  module: {
    loaders: [
      {
        exclude: /node_modules/,
        loader: 'babel',
        query: {
          presets: ['react', 'es2015', 'stage-1']
        }
      }
    ]
  },
  resolve: {
    extensions: ['', '.js', '.jsx']
  },
  devServer: {
    historyApiFallback: true,
    contentBase: './',
    watchOptions: {
      aggregateTimeout: 300,
      poll: 1000
    }
  }
};

这是我的package.json：

{
  "name": "redux-simple-starter",
  "version": "1.0.0",
  "description": "Simple starter package for Redux with React and Babel support",
  "main": "index.js",
  "repository": "git@github.com:StephenGrider/ReduxSimpleStarter.git",
  "scripts": {
    "dev": "node ./node_modules/webpack-dev-server/bin/webpack-dev-server.js",
    "postinstall":  "webpack -p",
    "start" : "node server.js" , 
    "test": "mocha --compilers js:babel-core/register --require ./test/test_helper.js --recursive ./test",
    "test:watch": "npm run test -- --watch"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "babel-core": "^6.2.1",
    "babel-loader": "^6.2.0",
    "babel-preset-es2015": "^6.1.18",
    "babel-preset-react": "^6.1.18",
    "webpack": "^1.12.9",
    "webpack-dev-server": "^1.14.0"
  },
  "dependencies": {
    "babel-preset-stage-1": "^6.1.18",
    "loadash": "^1.0.0",
    "lodash": "^3.10.1",
    "prop-types": "^15.6.2",
    "react": "^16.3.2",
    "react-dom": "^16.3.2",
    "react-redux": "5.0.7",
    "react-router": "^3.2.0",
    "react-transition-group": "^2.4.0",
    "redux": "4.0.0",
    "redux-form": "^5.3.6"
  }
}

还有我的server.js：

const express = require ('express')
const path = require ('path')
const port = process.env.PORT || 8080 ; //اگه پورت توسط هیروکو داده شده بود ازش استفاده میکنیم در غیر این صورت پورت 8080
const app = express()

app.use (express.static(__dirname))
app.get ("*" , (req,res) =>{ //تمام ادرس ها رو میفرستیم برای index.html
  res.sendFile(path.resolve(__dirname, 'index.html'))
});

app.listen(port)
console.log("server started" +__dirname) ;

将项目部署到heroku之后，在控制台中出现以下错误：“未捕获的错误：找不到模块“ React””

我在做什么错了？