added test to ensure event ordering
added test to ensure event ordering

* based on w3c spec https://xhr.spec.whatwg.org/#request-error-steps

cjohansen/Sinon.JS,mroderick/Sinon.JS,mroderick/Sinon.JS,Khan/Sinon.JS,Khan/Sinon.JS,cjohansen/Sinon.JS,timwienk/sinon,andpor/sinon,jishi/sinon,fatso83/Sinon.JS,fatso83/Sinon.JS,andpor/sinon,mroderick/Sinon.JS,timwienk/sinon,fatso83/Sinon.JS,jishi/sinon,jishi/sinon,cjohansen/Sinon.JS,andpor/sinon,timwienk/sinon,Khan/Sinon.JS