Ensure that index responses are unicode even when simplejson tries to break them.
Use a new bucket for index decoding test to avoid stale keys.
Override the correct attribute, dummy.
Merge branch 'feature/issue-852-unicode-index-lookups' into develop
Merge branch 'develop' into feature/issue-850-riak-paginated-indexes

Conflicts:
	vumi/persist/riak_manager.py
	vumi/persist/txriak_manager.py