Fixing a bug in the bot ignore logic to use sender.

Summary: Also added sender to the campfire adapter. This isn't extremely useful as it's just a numeric id, but it allows us to add ignores (specifically having the bot ignore itself).

Test Plan: Ran the bot, ignored itself.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4893