Fix the integration test in a PR, as it will need review by Toby.

There are two failures atm:

1) eZ\Publish\API\Repository\Tests\ContentTypeServiceTest::testCreateContentTypeInTransactionWithRollback
eZ\Publish\Core\Base\Exceptions\InvalidArgumentException: Argument 'position' is invalid: '0' is wrong value in class FieldDefinition, an integer strictly greater than 0 is required.

/Users/andrerom/Sites/www/next/eZ/Publish/Core/Persistence/Legacy/Content/Type/Handler.php:262
/Users/andrerom/Sites/www/next/eZ/Publish/Core/Persistence/Legacy/Content/Type/Handler.php:244
/Users/andrerom/Sites/www/next/eZ/Publish/Core/Repository/ContentTypeService.php:533
/Users/andrerom/Sites/www/next/eZ/Publish/API/Repository/Tests/ContentTypeServiceTest.php:2914

2) eZ\Publish\API\Repository\Tests\ContentTypeServiceTest::testCreateContentTypeInTransactionWithCommit
eZ\Publish\Core\Base\Exceptions\InvalidArgumentException: Argument 'position' is invalid: '0' is wrong value in class FieldDefinition, an integer strictly greater than 0 is required.

/Users/andrerom/Sites/www/next/eZ/Publish/Core/Persistence/Legacy/Content/Type/Handler.php:262
/Users/andrerom/Sites/www/next/eZ/Publish/Core/Persistence/Legacy/Content/Type/Handler.php:244
/Users/andrerom/Sites/www/next/eZ/Publish/Core/Repository/ContentTypeService.php:533
/Users/andrerom/Sites/www/next/eZ/Publish/API/Repository/Tests/ContentTypeServiceTest.php:2983