[
 {
 "id": 1,
 "username": "Emanuel",
 "email": "emanuel",
 "password": "123",
 "created_at": "2018-01-17T12:04:43.000Z",
 "updated_at": "2018-01-17T12:04:43.000Z"
 }
]

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';

@Injectable()
 export class RestProvider {

  constructor(public http: HttpClient) {
   console.log('Hello RestProvider Provider');
  }

 apiUrl = 'http://localhost:3000';

 getUsers(){
  return new Promise(resolve => {
    this.http.get(this.apiUrl+'/users').subscribe(data => {
        console.log(data);
    }, err => {
        console.log(err);
    });
  });
 }
}