In my case I have a `http_proxy` env variable on my development computer which passes all traffic to my vpn, however this proxy would fail to work when hostname is `localhost`, therefore when I'm testing my application it always fails because I setup my server at localhost, I want a method to force axios receiving a `none` for proxy config, currently if `proxy` property is `null` or `undefined` it will use the `http_proxy` env
test/unit/adapters/http.js
test.deepEqual(res.data, data);
        test.done();
      });
    });
  },
  testRedirect: function (test) {
    var str = 'test response';
    server = http.createServer(function (req, res) {
      var parsed = url.parse(req.url);
      if (parsed.pathname === '/one') {
        res.setHeader('Location', '/two');
        res.statusCode = 302;
        res.end();
      } else {
        res.end(str);
      }
    }).listen(4444, function () {
      axios.get('http://localhost:4444/one').then(function (res) {
        test.equal(res.data, str);
        test.equal(res.request.path, '/two');
        test.done();
      });
    });
  },
  testNoRedirect: function (test) {
    server = http.createServer(function (req, res) {
      res.setHeader('Location', '/foo');
      res.statusCode = 302;
      res.end();
    }).listen(4444, function () {