RocketChat integration

[laliluna]

I created this pull request in rocket chat, so that the roles are included in the ticket.

RocketChat/Rocket.Chat#20382

RocketChat has a different structure and it would make their token unelegant, if I added the moderator flag directly to the body. The roles will be included in body["context"]["user"]["roles"] as at least empty table.

Even if the pull request is accepted, it would require changes. I am unexperienced with lua plugins. Is there a way to customize which field to use?

Cheers Sebastian