[5.5] Allow disabling of specific middleware in tests

[brayniverse]

withoutMiddleware is useful in tests, however, because implicit bindings are resolved in middleware, disabling all middleware classes is not ideal (as mentioned in this issue). Therefore, this PR allows you to disable specific middleware classes.

$this->withoutMiddleware([
    \Illuminate\Auth\Middleware\Authenticate::class,
    \App\Http\Middleware\VerifyCsrfToken::class,
]);

$this->withoutMiddleware(ExampleMiddleware::class);

[sisve]

This change broke the compatibility with laravel/browser-kit-testing. Filed an issue at laravel/browser-kit-testing#44

My fault. The browser kit testing expects you to extend Laravel\BrowserKitTesting\TestCase, which I forgot.