public IHttpActionResult Post(ContactoModel model)
        {
            // Provisional
            model.Fecha = DateTime.Now;

            var data = ContactoRepositorio.Add(model);

            if (data == null)
                return BadRequest();

            return Ok(data);
        }
        public async void AgregarContacto(UsuarioModel model)
        {
            var cm = new ContactoModel
            {
                IdUsuario = Session.User.Id,
                IdAmigo = model.Id,
                Fecha = DateTime.Now
            };

            await _servicio.AddContacto(cm);
            await new Page().DisplayAlert(model.NombreCompleto, "Contacto agregado", "OK");

        }
        public async Task<ContactoModel> AddContacto(ContactoModel model)
        {
            var request = new RestRequest("Contacto", Method.POST);
            request.AddJsonBody(model);
            var response = await _client.Execute<ContactoModel>(request);

            if (response.IsSuccess)
                return response.Data;
            return null;
        }