I have axios@0.15.2

If this HTML is run, some requests will be cancelled by Chrome:

    <html>
    <head>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/axios/0.15.2/axios.js"></script>
    </head>
        <script>
        var promises = [];
        window.onload = function() {
            for (var i = 0; i < 4; i++) {
                var promise = axios.get('some url which causes ERR_CONNECTION_CLOSED');
                promises.push(promise);
            }
        }
       </script>
    </html>

![Cancelled](https://cloud.githubusercontent.com/assets/4506837/20349972/9123cef0-ac2e-11e6-93db-0ec66f205382.png)

But promises which turned into cancelled request won't be fulfilled:

![notfulfilled](https://cloud.githubusercontent.com/assets/4506837/20350023/d2146c4e-ac2e-11e6-89bc-983233628d09.png)

test/specs/requests.spec.js
describe('requests', function () {
  beforeEach(function () {
    jasmine.Ajax.install();
  });
  afterEach(function () {
    jasmine.Ajax.uninstall();
  });
  it('should treat single string arg as url', function (done) {
    axios('/foo');
    getAjaxRequest().then(function (request) {
      expect(request.url).toBe('/foo');
      expect(request.method).toBe('GET');
      done();
    });
  });
  it('should treat method value as lowercase string', function (done) {
    axios({
      url: '/foo',
      method: 'POST'
    }).then(function (response) {
      expect(response.config.method).toBe('post');
      done();
    });
    getAjaxRequest().then(function (request) {
      request.respondWith({
        status: 200
      });
    });
  });