Update driver to nodejs/cloudant

[jannyHou]

See parent spike story https://github.com/strongloop/loopback-connector-cloudant/issues/214

Acceptance Criteria

• [x] Update driver to https://github.com/cloudant/nodejs-cloudant
• [x] Find a new db (support partition)for test
  • The docker one is retired and don't support partition
  • Check the couchdb2 image as well, and replace it with a new one if necessary. (since 95% of the code are written in loopback-connector-couchdb2)

[jannyHou]

The new docker image: https://hub.docker.com/r/ibmcom/couchdb3

[emonddr]

@jannyHou have you submitted a PR for this yet? Is this possible for October?

[jannyHou]

@emonddr I have code change on local, haven't created the PR. I see a PR updating the docker image https://github.com/strongloop/loopback-connector-cloudant/pull/223#pullrequestreview-303991999, it would be better if we can upgrade to use https://hub.docker.com/r/ibmcom/couchdb3.

[emonddr]

223 (review)

@agnes512 closed this PR after we had a discussion, and she realized it wasn't needed.

[jannyHou]

closed as https://github.com/strongloop/loopback-connector-cloudant/pull/224 landed