message: update json payment protocol example
  Reviewers: arik, bigly, kevin
  Subscribers: ben
diff: @@ -28,8 +28,16 @@ co(function *run() {
  console.log(`Are you sure you want to send ${info.sum} to merchant?`);
  console.log(`Merchant memo: ${info.memo}`);
  - // TODO: insert wallet passphrase here
  - info.walletPassphrase = null;
  + const txParams = {
  + recipients: info.recipients,
  + walletPassphrase: null, // TODO: insert wallet passphrase here
  + minConfirms: 1, // jsonPaymentProtocol requires all inputs be confirmed
  + enforceMinConfirmsForChange: true
  + };
  +
  + const tx = yield wallet.prebuildAndSignTransaction(txParams);
  +
  + info.txHex = tx.txHex;
  const res = yield wallet.sendPaymentResponse(info);
  console.dir(res);
  