Laravel 5.1 doesn't allow you to pass in url params (is there configuration)

Consider the following test:

public function it_should_contain_a_list_of_investors_who_belong_to_one_or_more_investment() {
    $this->createInvestment();

    $investor = factory(User::class)->create([
        'role_id' => 4
    ]);

    $response = $this->actingAs($investor)
                     ->call('GET', 'api/v1/investors?include=investments');

    dd(json_decode($response->getContent()));
    $this->assertNotEmpty(json_decode($response->getContent()));
}

Now consider the following action this test is calling:

public function getAllInvestorsForCompany($slug)
{
    $users = $this->investorEntity->usersForCompany($slug);

    $resource = new Collection($users, new InvestorTransformer, 'investor');
    dd($_GET);
    if (isset($_GET['include'])) {
        $usersData = $this->manager->parseIncludes($_GET['include'])->createData($resource)->toArray();
    } else {
        $usersData = $this->manager->createData($resource)->toArray();
    }

    return response()->json($usersData);
}

Note the dd, the $_GET returns []

Lets do the same test in the browser:

array:1 [▼
  "include" => "investments.offering.company"
]

Ok so in the browser I get back investments.offering.company, because that is what I am passing in as the ?include= But in the test its like laravel ignores the ?include and moves on.

is this a default behaviour of laravel 5.1 tests and if so how do I shut it off?