twitter: send log level messages

We note interesting things we're doing a log level, so sending it to
twitter, where we have about 375 people who were engaged enough to
follow us, seems like a way to increase visibility with what is going
on in the project.

Change-Id: I59189d71fb6a3618b14947033d8cc0bf70d8d0b1

statusbot/bot.py

@@ -282,7 +282,7 @@ class Tweet(UpdateInterface):
         self.update(msg)
 
     def log(self, msg=None):
-        pass
+        self.update(msg)
 
     def ok(self, msg=None):
         if msg: