In my case it wouldn't enough to include only map and promise:
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/toPromise';
I solved this problem by importing several rxjs components as official documentation recommends:
1) Import statements in one app/rxjs-operators.ts file:
// import 'rxjs/Rx'; // adds ALL RxJS statics & operators to Observable
// See node_module/rxjs/Rxjs.js
// Import just the rxjs statics and operators we need for THIS app.
// Statics
import 'rxjs/add/observable/throw';
// Operators
import 'rxjs/add/operator/catch';
import 'rxjs/add/operator/debounceTime';
import 'rxjs/add/operator/distinctUntilChanged';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/switchMap';
import 'rxjs/add/operator/toPromise';
2) Import rxjs-operator itself in your service:
// Add the RxJS Observable operators we need in this app.
import './rxjs-operators';