test(switch): fix odd-looking test with Promises
test(switch): fix odd-looking test with Promises

For issue #1450.

jayphelps/rxjs,trxcllnt/RxJS,figueredo/RxJS,Brocco/RxJS,robwormald/RxJS,adrianomelo/RxJSNext,kwonoj/RxJS,jayphelps/rxjs,ReactiveX/RxJS,Igorbek/rxjs5,Brocco/RxJS,trxcllnt/RxJS,ReactiveX/RxJS,Brocco/RxJS,SangKa/RxJS-Docs-CN,benlesh/RxJS,ReactiveX/RxJS,elliotschi/rxjs,trxcllnt/RxJS,benlesh/RxJS,SangKa/RxJS-Docs-CN,jayphelps/rxjs,ReactiveX/RxJS,kwonoj/RxJS,robwormald/RxJS,ReactiveX/rxjs,saneyuki/RxJS,martinsik/rxjs,trxcllnt/RxJS,ReactiveX/rxjs,martinsik/rxjs,adrianomelo/RxJSNext,robwormald/RxJS,adrianomelo/RxJS-1,adrianomelo/RxJSNext,adrianomelo/RxJS-1,robwormald/RxJS,benlesh/RxJS,martinsik/rxjs,kwonoj/RxJS,Igorbek/rxjs5,martinsik/rxjs,SangKa/RxJS-Docs-CN,elliotschi/rxjs,RxJS-CN/RxJS-Docs-CN,benlesh/RxJS,IgorMinar/RxJS,gluck/RxJS,Igorbek/rxjs5,adrianomelo/RxJSNext,jayphelps/rxjs,RxJS-CN/RxJS-Docs-CN,saneyuki/RxJS,RxJS-CN/RxJS-Docs-CN,staltz/RxJSNext,SangKa/RxJS-Docs-CN,figueredo/RxJS,staltz/RxJSNext,Brocco/RxJS,adrianomelo/RxJS-1,ReactiveX/rxjs,IgorMinar/RxJS,RxJS-CN/RxJS-Docs-CN,staltz/RxJSNext,figueredo/RxJS,gluck/RxJS,ReactiveX/rxjs,adrianomelo/RxJS-1,jayphelps/rxjs,figueredo/RxJS,gluck/RxJS,staltz/RxJSNext,kwonoj/RxJS,gluck/RxJS,Igorbek/rxjs5,elliotschi/rxjs,elliotschi/rxjs