Testing unauthorized user restriction in Laravel PHPUnit

Laravel Version 5.2

In my project, users with role_id = 4 has the admin role and can manage users.

I have defined the following ability in AuthServiceProvider:

public function boot(GateContract $gate)
{
    $this->registerPolicies($gate);

    $gate->define('can-manage-users', function ($user)
    {
        return $user->role_id == 4;
    });
}

I have used this ability in the UserController __construct method as follows:

public function __construct()
{
    $this->authorize('can-manage-users');
}

In ExampleTest, I have created two tests to check if the defined authorization works.

The first test for admin user who has role_id = 4. This test passes.

public function testAdminCanManageUsers()
{
    $user = Auth::loginUsingId(1);
    $this->actingAs($user)
        ->visit('users')
        ->assertResponseOk();
}

The second test is for another user who does not have role_id = 4. I have tried with response status 401 and 403. But the test is failing:

public function testNonAdminCannotManageUsers()
{
    $user = Auth::loginUsingId(4);
    $this->actingAs($user)
        ->visit('users')
        ->assertResponseStatus(403);
}

First few lines of the failure message is given below:

A request to [http://localhost/users] failed. Received status code [403].

C:\wamp\www\laravel\blog\vendor\laravel\framework\src\Illuminate\Foundation\Testing\Concerns\InteractsWithPages.php:196 C:\wamp\www\laravel\blog\vendor\laravel\framework\src\Illuminate\Foundation\Testing\Concerns\InteractsWithPages.php:80 C:\wamp\www\laravel\blog\vendor\laravel\framework\src\Illuminate\Foundation\Testing\Concerns\InteractsWithPages.php:61 C:\wamp\www\laravel\blog\tests\ExampleTest.php:33

Caused by exception 'Illuminate\Auth\Access\AuthorizationException' with message 'This action is unauthorized.' in C:\wamp\www\laravel\blog\vendor\laravel\framework\src\Illuminate\Auth\Access\HandlesAuthorization.php:28

I have also tried to use 'see' method as follows:

public function testNonAdminCannotManageUsers()
{
    $user = Auth::loginUsingId(4);
    $this->actingAs($user)
        ->visit('users')
        ->see('This action is unauthorized.');
}

But it's failing too. What am I doing wrong? How can I make the test pass?