#### 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
return toString.call(val) === '[object Array]';
}
/**
 * Determine if a value is a Node Buffer
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Node Buffer, otherwise false
 */
function isBuffer(val) {
  return ((typeof Buffer !== 'undefined') && (Buffer.isBuffer) && (Buffer.isBuffer(val)));
}
/**
 * Determine if a value is an ArrayBuffer
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an ArrayBuffer, otherwise false
 */
function isArrayBuffer(val) {
  return toString.call(val) === '[object ArrayBuffer]';
}
/**
 * Determine if a value is a FormData
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an FormData, otherwise false
 */
function isFormData(val) {