title: Can't find @angular/common/http on stackblitz
body: <p>I try to create a new service file on Stackblitz, for some reason I get an error message: Can't find module '@angular/common/http'</p>
  
  <p>Same with 'rxjs/Observable'; any idea why? It uses now Angular 6. </p>
  
  <p>I have the @angular/http under npm packages</p>
  
  <p>Thanks. </p>