Test pierwszy - dla 1 powinna być pusta tablica

PrimeFactorsSpec.php

<?php

namespace spec\Kata;

use PhpSpec\ObjectBehavior;
use Prophecy\Argument;

class PrimeFactorsSpec extends ObjectBehavior
{
    public function it_return_empty_array_for_1()
    {
        $this->factorize(1)->shouldReturn([]);
    }
}