public function run()
 {
     QuestionAnswer::truncate();
     $faker = Faker\Factory::create();
     $authorIds = User::lists('id');
     $questionIds = Question::lists('id');
     for ($i = 0; $i < 10; $i++) {
         QuestionAnswer::create(['answer' => $faker->sentence, 'status' => $faker->randomElement(array(0, 1)), 'question_id' => $faker->randomElement($questionIds), 'author_id' => $faker->randomElement($authorIds)]);
     }
 }