use DatabaseTransactions; not working, phpunit inserting in db

I'm making a test with PhpUnit and Laravel 5.1

I'm using

 use DatabaseTransactions;

So that my test does not really insert data into my database.

But I can notice that in fact, it is inserting, so for each test, I have to delete the row in db, it is kind of annoying... Any idea why???

Here is my test class:

<?php

use App\User;
use Illuminate\Foundation\Testing\DatabaseTransactions;
use Illuminate\Support\Facades\Lang;

class AuthTest extends TestCase
{
    use DatabaseTransactions;


    /** @test */
    public function a_user_may_register_for_an_account_but_must_confirm_their_email_address()
    {
        // When we register...
        $this->visit('/auth/register')
            ->type('JohnDoe', 'name')
            ->type('john@example.com', 'email')
            ->type('john@example.com', 'email_confirmation')
            ->type('password', 'password')
            ->type('password', 'password_confirmation')
            ->press(Lang::get('auth.create_account'));
        // We should have an account - but one that is not yet confirmed/verified.
        $this->see(htmlentities(Lang::get('auth.check_your_email')))
            ->seeInDatabase('users', ['name' => 'JohnDoe', 'verified' => 0]);
        $user = User::whereName('JohnDoe')->first();
        // You can't login until you confirm your email address.
        $this->login($user)->see(Lang::get('auth.account_not_activated'));
        $this->visit("auth/register/confirm/{$user->token}")
            ->see(Lang::get('auth.tx_for_confirm'))
            ->seeInDatabase('users', ['name' => 'JohnDoe', 'verified' => 1]);
    }



    protected function login($user = null)
    {
        $user = $user ?: $this->factory->create('App\User', ['password' => 'password']);
        return $this->visit('/auth/login')
            ->type($user->email, 'email')
            ->type('password', 'password')
            ->press(Lang::get('auth.signin'));
    }

    /** @test */
    public function login_standard_user()
    {
        return $this->visit('auth/login')
            ->type('user@user.com', 'email')
            ->type('user', 'password')
            ->press(Lang::get('auth.signin'));
    }

    /** @test */
    public function login_admin_user()
    {
        return $this->visit('auth/login')
            ->type('admin@admin.com', 'email')
            ->type('admin', 'password')
            ->press(Lang::get('auth.signin'));
    }
}

via Chebli Mohamed