refactor: remove src/operators.ts re-export
refactor: remove src/operators.ts re-export

* This re-export was added to support CJS and internal require statements.
Those internal requires were require('rxjs/operators') and with SystemJS
this would try to find a "rxjs/operators.js" file. Now that the internal
references have changed to deep imports, we should remove this re-export
to ensure we don't again add internal references to rxjs/operators.

ReactiveX/RxJS,Brocco/RxJS,martinsik/rxjs,benlesh/RxJS,benlesh/RxJS,Brocco/RxJS,ReactiveX/rxjs,ReactiveX/RxJS,martinsik/rxjs,kwonoj/RxJS,Brocco/RxJS,kwonoj/RxJS,ReactiveX/RxJS,jayphelps/rxjs,ReactiveX/rxjs,jayphelps/rxjs,kwonoj/RxJS,IgorMinar/RxJS,martinsik/rxjs,trxcllnt/RxJS,ReactiveX/RxJS,Brocco/RxJS,trxcllnt/RxJS,jayphelps/rxjs,kwonoj/RxJS,ReactiveX/rxjs,IgorMinar/RxJS,martinsik/rxjs,benlesh/RxJS,jayphelps/rxjs,trxcllnt/RxJS,jayphelps/rxjs,trxcllnt/RxJS,benlesh/RxJS,ReactiveX/rxjs