Error on electron

[goodhyun]

const fetch = require('node-fetch');
is causing the following error on an electron/webkit environment

 WARNING in ./~/encoding/lib/iconv-loader.js
Critical dependencies:
9:12-34 the request of a dependency is an expression
 @ ./~/encoding/lib/iconv-loader.js 9:12-34

It'd be okay. We can use the browser's built-in fetch.

What would be a nicer mitigation on this problem than just to comment them out ??

[ndaidong]

Please check this issue #41 if it gives you some ideas?