Remove extract_comments in housekeeper bot.

BUG=skia:

Change-Id: I6bd745a03c9f8c06ed711839a4bda1db0693cf5a
Reviewed-on: https://skia-review.googlesource.com/9220
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Joe Gregorio <jcgregorio@google.com>
3 files changed