truffle.js

// Allows us to use ES6 in our migrations and tests.
require('babel-register')
var bip39 = require("bip39");
var hdkey = require('ethereumjs-wallet/hdkey');
var ProviderEngine = require("web3-provider-engine");
var WalletSubprovider = require('web3-provider-engine/subproviders/wallet.js');
var Web3Subprovider = require("web3-provider-engine/subproviders/web3.js");
var Web3 = require("web3");

// Get our mnemonic and create an hdwallet
var mnemonic = "At the edge of our hope, at the end of our time, we have chosen not only to believe in ourselves, but in each other";
var hdwallet = hdkey.fromMasterSeed(bip39.mnemonicToSeed(mnemonic));

// Get the first account using the standard hd path.
var wallet_hdpath = "m/44'/60'/0'/0/";
var wallet = hdwallet.derivePath(wallet_hdpath + "0").getWallet();
var address = "0x" + wallet.getAddress().toString("hex");

var providerUrl = "https://ropsten.infura.io/c72adYaVKozBHnFEYqCy";
var engine = new ProviderEngine();
engine.addProvider(new WalletSubprovider(wallet, {}));
engine.addProvider(new Web3Subprovider(new Web3.providers.HttpProvider(providerUrl)));

// log new blocks
engine.on('block', function(block){
  console.log('================================')
  console.log('BLOCK CHANGED:', '#'+block.number.toString('hex'), '0x'+block.hash.toString('hex'))
  console.log('================================')
})

// network connectivity error
engine.on('error', function(err){
  // report connectivity errors
  console.error(err.stack)
})


engine.start(); // Required by the provider engine.

module.exports = {
  networks: {
    ropsten: {
      network_id: 3,    // Official ropsten network id
      provider: engine, // Use our custom provider
      from: address,     // Use the address we derived
      gas: 3000000
    }
  },
  rpc: {
    // Use the default host and port when not using ropsten
    host: "localhost",
    port: 8545
  }
};