Doesn't write bundles inside build directory when using webpack 2

[saeidalidadi]

I am using webpack with the following config:

/**
 * Require Browsersync along with webpack and middleware for it
 */
var browserSync = require('browser-sync');
var webpack = require('webpack');
var webpackDevMiddleware = require('webpack-dev-middleware');
var webpackHotMiddleware = require('webpack-hot-middleware');

/**
 * Require ./webpack.config.js and make a bundler from it
 */
var webpackConfig = require('./webpack.dev.config');
var bundler = webpack(webpackConfig);
console.log(webpackConfig.output.publicPath);
/**
 * Run Browsersync and use middleware for Hot Module Replacement
 */
browserSync({
    server: {
      baseDir: 'app',

      middleware: [
        webpackDevMiddleware(bundler, {
          // IMPORTANT: dev middleware can't access config, so we should
          // provide publicPath by ourselves
          publicPath: webpackConfig.output.publicPath,

          // pretty colored output
          stats: { colors: true }

          // for other settings see
          // http://webpack.github.io/docs/webpack-dev-middleware.html
        }),

        // bundler should be the same as above
        webpackHotMiddleware(bundler)
      ]
    },

    // no need to watch '*.js' here, webpack will take care of it for us,
    // including full page reloads if HMR won't work
    files: [
      'app/css/*.css',
      'app/*.html'
    ]
});

webpack.dev.config.js

const path = require('path');
const webpack = require('webpack');
const phaserModule = path.join(__dirname, '/node_modules/phaser/');
const phaser = path.join(phaserModule, 'build/custom/phaser-split.js'),
  
  pixi = path.join(phaserModule, 'build/custom/pixi.js'),
  p2 = path.join(phaserModule, 'build/custom/p2.js');

module.exports = {
    //context: path.join(__dirname, 'app/src'),
    entry: {
      app: path.resolve(__dirname, 'app/src/app.js'),
      vendors: [
        'phaser',
        'webpack/hot/dev-server',
        'webpack-hot-middleware/client',
      ]
    },
    output: {
      publicPath: path.resolve(__dirname, 'app/build/'),
      path: path.resolve(__dirname, 'app/build'),
      filename: '[name].bundle.js'
    },
    module: {
      rules: [
        {
          test: /\.js$/,
          exclude: /(node_modules)/,
          use: [
            {
              loader: 'babel-loader',
              options: {
                presets: ['env', 'es2015'],
                cacheDirectory: true
              }
            }
          ],
          test: [/\pixi.js/, /\p2.js/],
          use: [
            {
              loader: 'script-loader'
            }
          ]
        }
      ]
    },
    resolve: {
      alias: {
        'phaser': phaser,
          'pixi.js': pixi,
          'p2': p2,
      }
    },
    plugins: [
      new webpack.optimize.CommonsChunkPlugin({
        name: 'vendors' // Specify the common bundle's name.
      }),
      new webpack.optimize.OccurrenceOrderPlugin(),
      new webpack.HotModuleReplacementPlugin(),
      new webpack.NoEmitOnErrorsPlugin()
    ],
    target: 'web'
}

When I do bundling with webpack cli its ok, but it doesnt load my bundles after bundling from node devserver.js