Fix user brain getting overwritten

* This works around hubotio/hubot#670
* hubot's userForId checks if the current room is different than the one
  that was last recorded for the user; if it's different, it overwrites
  the entire record for that user.

Author: Ari Pollak

adapter.coffee

@@ -65,7 +65,7 @@ class Zulip extends Adapter
             author = @robot.brain.userForId msg.sender_email,
                 name: msg.sender_full_name
                 email_address: msg.sender_email
-                room: room
+            author.room = room
 
             content = msg.content.replace(@mention_regex, '@$1')
             console.log(@mention_regex, content)