Error: Unreachable code detected ionic 3 weather app

Ok, so I am following along the traversy media tutorial on ionic 3, and when i get to the part where you create a provider I get and error that says unreachable code detected in here:

.map((res: Response) => res.json() );

and it also says on typescript

cannot find the name 'map' did you mean 'Map'?

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import 'rxjs/add/operator/map';

@Injectable()
export class WeatherProvider {
  apiKey = "89cca14f4ffcd27d602ad5e587f8e17f";
  url;

 constructor(public http: HttpClient) {
   console.log('Hello WeatherProvider Provider');
   this.url = "api.openweathermap.org/data/2.5/weather?q=";
 }



 getWeather(city, country){
 return this.http.get(this.url+city+','+country);
   .map((res: Response) => res.json() );
 }

}