bulk_delete returns None, even when no errors occur

[nfvs]

I've uploaded a python script to demonstrate it. It creates 3 documents, executes bulk_delete on them and prints the return value.
I'm using couchdbkit from source, updated and tested today (Sep 20)

<link-removed, no longer necessary>

To run: python couchdbkit-bulkdelete.py http://couchdb-url:5984

[benoitc]

fixed in last head. thanks for the test :)