So this is a little self serving, but I think we should consider dropping support for IE9.  The data is interesting.  I'm seeing a [0.6% browser market share for IE9](https://netmarketshare.com/browser-market-share.aspx?options=%7B%22filter%22%3A%7B%22%24and%22%3A%5B%7B%22deviceType%22%3A%7B%22%24in%22%3A%5B%22Desktop%2Flaptop%22%5D%7D%7D%5D%7D%2C%22dateLabel%22%3A%22Trend%22%2C%22attributes%22%3A%22share%22%2C%22group%22%3A%22browserVersion%22%2C%22sort%22%3A%7B%22share%22%3A-1%7D%2C%22id%22%3A%22browsersDesktopVersions%22%2C%22dateInterval%22%3A%22Monthly%22%2C%22dateStart%22%3A%222017-07%22%2C%22dateEnd%22%3A%222018-06%22%2C%22segments%22%3A%22-1000%22%2C%22pageLength%22%3A50%7D).

What's neat about that data is that IE8 has twice the usage of IE9 🤷‍♂️ And IE10 has only 0.54% market share!  I could make a reasonable argument for dropping both IE9 *and* IE10.  

Of course, I'm only looking at this because I'd very much like to ship a new npm module with a few recently merged changes, and the IE9 tests are failing :)  

What are folks thoughts?  Does anyone feel strongly about the IE support matrix as it stands today?

@nickuraltsev @mzabriskie 
test/specs/__helpers.js
jasmine.Ajax.uninstall();
  });
  it('should accept HTTP Basic auth with username/password', function (done) {
    axios('/foo', {
      auth: {
        username: 'Aladdin',
        password: 'open sesame'
      }
    });
    setTimeout(function () {
      var request = jasmine.Ajax.requests.mostRecent();
      expect(request.requestHeaders['Authorization']).toEqual('Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==');
      done();
    }, 100);
  });
  it('should fail to encode HTTP Basic auth credentials with non-Latin1 characters', function (done) {
    axios('/foo', {
      auth: {
        username: 'Aladßç£☃din',
        password: 'open sesame'
      }
    }).then(function(response) {
      done(new Error('Should not succeed to make a HTTP Basic auth request with non-latin1 chars in credentials.'));
    }).catch(function(error) {
      validateInvalidCharacterError(error);
      done();
    });
  });
};