Warning on PHP Unit test

Warning on PHP Unit test

```
1) KiwiCommerce\AdminActivity\Test\Unit\Model\ProcessorTest::testValidate
This test did not perform any assertions

/code/Test/Unit/Model/ProcessorTest.php:143

/composer/vendor/phpunit/phpunit/src/TextUI/Command.php:206
/composer/vendor/phpunit/phpunit/src/TextUI/Command.php:162
```