Leave out messages on API conversations index

Task #399
Fix bug when listing messages in api
Merge pull request #181 from pksunkara/listing_messages_api

Fix bug when listing messages in api
Apiary docs are in sync with live api
Merge pull request #182 from pksunkara/apiary

Apiary docs are in sync with live api
Fix tab to spaces
Change to include
Merge pull request #180 from wesleylancel/api-disable-messages

Leave out messages on API conversations index, task #401