If either the edit creation or edit publishing fail, we're left with
an unpublished edit hanging around. This can result in a follow-up
invocation of 'git cl desc' (e.g. if the user changes their mind, or
retries) will also fail. So, clean up after ourselves.

BUG=671091

Change-Id: Icfe53996acf2555b82be0695a3c86ebb8c50b936
Reviewed-on: https://chromium-review.googlesource.com/418449Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Aaron Gable <agable@chromium.org>