Validation error when creating a new category: "meta_description is not yet defined as an attribute of Category"

[elvetemedve]

I failed to create a new category with MageTest.

Code to reproduce issue:

$fixtureGenerator = $this->getMainContext()->getFixture('category');
$defaultStoreId = 1;
$parentCategoryId = 1;
$categoryData = array(
  'name' => 'Behat Test',
  'is_active' => '1',
  'meta_description' => 'Test description.',
  'store_id' => $defaultStoreId,
  'path_ids' => 
  array (
    $parentCategoryId,
  )
);
$fixtureGenerator->create($categoryData);

Actual result: I get the following error message: "meta_description is not yet defined as an attribute of Category"

Expected result: A new category created with the name "Behat Test".