can't make phpunit configurations to work with DatabaseMigrations trait

here is my phpunit.xml file :

<?xml version="1.0" encoding="UTF-8"?>
<phpunit backupGlobals="false"
     backupStaticAttributes="false"
     bootstrap="bootstrap/autoload.php"
     colors="true"
     convertErrorsToExceptions="true"
     convertNoticesToExceptions="true"
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false">
   <testsuites>
    <testsuite name="Feature">
        <directory suffix="Test.php">./tests/Feature</directory>
    </testsuite>

    <testsuite name="Unit">
        <directory suffix="Test.php">./tests/Unit</directory>
    </testsuite>
    </testsuites>
    <filter>
    <whitelist processUncoveredFilesFromWhitelist="true">
        <directory suffix=".php">./app</directory>
    </whitelist>
    </filter>
    <php>
    <env name="APP_ENV" value="testing"/>
    <env name="DB_CONNECTION" value="sqlite"/>
    <env name="DB_DATABASE" value=":memory:"/>
    <env name="CACHE_DRIVER" value="array"/>
    <env name="SESSION_DRIVER" value="array"/>
    <env name="QUEUE_DRIVER" value="sync"/>
</php>

here is my testclass :

<?php

namespace Tests\Feature;

use Illuminate\Foundation\Testing\DatabaseMigrations;
use Tests\TestCase;

class OrdersTest extends TestCase
{
    use DatabaseMigrations;

    /** @test */

    public function foobar()
    {
        $this->assertTrue(true);
    }
}

and i have database.sqlite file at database directory

when i run the test it's refresh my main database "mysql"