Add HeroService.getHeroesSlowly
Add HeroService.getHeroesSlowly

https://angular.io/docs/ts/latest/tutorial/toh-pt4.html#!#appendix-take-it-slow

thejohnfreeman/angular2-tour-of-heroes,thejohnfreeman/angular2-tour-of-heroes,thejohnfreeman/angular2-tour-of-heroes