Doesn't pass the PouchDB test suite

[nolanlawson]

Steps to repro:

hub clone pouchdb/pouchdb
cd pouchdb
npm install jsondown
LEVEL_ADAPTER=jsondown npm run test-node

Fails on one of the first tests (1) test total_rows with a variety of criteria) with a document update conflict error.

For more info about how to set up your project to run the PouchDB test suite (e.g. in Travis) and how to debug, check out this guide. *down adapters that are known to pass the test include LevelDOWN, MemDOWN, localstorage-down, level-js, riakdown, and redisdown.