Direct messages to bot

[jerome-jutteau]

For now, you can only configure the bot to join a specific channel but won't respond to direct messages.
This could be an option to enable or disable

[jerome-jutteau]

note to dev:

1. update the list of rooms with type=direct and keep a list of creatorId.

e.g. https://webexapis.com/v1/rooms?type=direct

2. get messages from direct messages and provide personId (provided through creatorId)