#### Summary

It looks like latest version includes `buffer.js` on the browser bundle even if not actually used.
This makes axios bundle size **3 times bigger**, adding 22kB to the minified size (0.16.0 is 11.9 KB while 0.16.1 is 33.9kB).

#### Context

- axios version: v0.16.1

lib/utils.js
if (obj === null || typeof obj === 'undefined') {
    return;
  }
  
  if (typeof obj !== 'object' && !isArray(obj)) {
    
    obj = [obj];
  }
  if (isArray(obj)) {