fixing bulk updates to handle ES 1.0

From here: http://www.elasticsearch.org/guide/en/elasticsearch/reference/1.x/_return_values.html

"ok" has been removed from all response values, so the bulk updater is failing.
Update models.py
Update models.py

I am full of typos today.
Merge pull request #371 from g-clef/master

raise_on_bulk_item_failure not working with ES 1.0