swarming: format handlers_bot.py
swarming: format handlers_bot.py

Bug: 1073708
Change-Id: Ia87778ccd835641cb2b852b3c1a9ce9c716fbff4
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-py/+/2192559
Auto-Submit: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Reviewed-by: Junji Watanabe <aaef61ef98ffea505db831f310be2a0eb8492537@google.com>
Commit-Queue: Junji Watanabe <aaef61ef98ffea505db831f310be2a0eb8492537@google.com>
Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>

luci/luci-py,luci/luci-py,luci/luci-py,luci/luci-py