public function test_store()
{
$billet = factory(Billet::class)->make();
$assignor = factory(BilletAssignor::class)->create();
$repo = App::make(BilletRepository::class);
$student = factory(Student::class)->create();
$data = $billet->toArray();
$data['student_id'] = $student->id;
$store = $repo->store($data);
$this->assertInstanceOf(Billet::class, $store);
$this->assertInstanceOf(Carbon::class, $store->created_at);
$this->seeInDatabase('billets', ['id' => $store->id, 'student_id' => $student->id]);
}