Right redirect after payment

Updated transfers controller to redirect to user getting hours and not current user
El `user_path` de una cosa que no es un  `User` creo que no funciona del todo. Posiblemente sería
```ruby
redirect_to user_path(Account.find(transfer_params[:destination]).accountable)
```

En este caso sería interesante un spec (@PatriRor puedes echar una mano?):
```ruby
describe TransfersController do
  describe "create" do
    let(:user_1) { ... }
    let(:user_2) { ... }
    let(:account_1) { user_1.account }
    let(:account_2) { user_2.account }
    subject { post :create, source: account_1.id, destination: account_2.id, amount: 100 }

    before { sign_in user_1 }

    it "redirects to destination" do
      expect(subject).to redirect_to(user_2)
    end
  end
end
```