polr/tests/TestCase.php

<?php
use Illuminate\Foundation\Testing\DatabaseMigrations;
use Illuminate\Foundation\Testing\DatabaseTransactions;

class TestCase extends Laravel\Lumen\Testing\TestCase
{
    /**
     * Creates the application.
     *
     * @return \Laravel\Lumen\Application
     */
    use DatabaseTransactions;

    public function createApplication() {
        return require __DIR__.'/../bootstrap/app.php';
    }
}