**Describe the bug**
Unit test case failed :
  1) supports http with nodejs
       should pass errors for a failed stream:
     Error: Timeout of 30000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (***************...

**To Reproduce**
Use VS Code internal terminal to excute the unit test .

**Expected behavior**
UT should be excuted correctly.

**Environment:**
 - Axios Version: latest master
 - OS Version: Window 10

**Additional context/Screenshots**
![Capture](https://user-images.githubusercontent.com/46782518/70436361-136c5380-1ac4-11ea-87b5-203b2e46ebbf.PNG)

test/unit/adapters/http.js
var url = require('url');
var zlib = require('zlib');
var assert = require('assert');
var fs = require('fs');
var server, proxy;
describe('supports http with nodejs', function () {
  afterEach(function () {
    if (server) {
      server.close();
      server = null;
    }
    if (proxy) {
      proxy.close()
      proxy = null;
    }
    if (process.env.http_proxy) {
      delete process.env.http_proxy;
    }
    if (process.env.no_proxy) {
      delete process.env.no_proxy;
    }
  });
  it('should respect the timeout property', function (done) {
    server = http.createServer(function (req, res) {
      setTimeout(function () {
        res.end();
      }, 1000);
    }).listen(4444, function () {
      var success = false, failure = false;
      var error;