Add support for livewire blade directive

[leganz]

Setup:

Livewire component view file with the following content:

@livewire('component-x')

Testcase:

 Livewire::test(LivewireTestComponentC::class)
            ->assertContainsLivewireComponent(LivewireComponentX::class);

Current situation:

Test will fail cause the test method does not check for the appearance of the @ directive tags.

Changes:

The assert method will create regex for both appearances. That allows the useage of both.

[christophrumpel]

Thanks 👍 Will add a new release now.