Add user authentication function

# Road to Goal

- [x] Fix indent of User.php

- [x] Add setPasswordAttribute : to make hash password

- [x] Set dummy user (change HaikUsersTableSeeder)

- [x] Add auth routes for /haik-admin

- [x] Add login.blade.php to set login form

- [x] Add SessionController.php

- [x] Modify routes.php to connect SessionController

- [x] Add validation in SessionController->login()