test(Observable): add tests for important lift() features
test(Observable): add tests for important lift() features

Add tests for Observable to verify that the most important codebase-wide features brought by the
lift architecture are satisfied.

Refers to discussion in #60.

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