[autotest] Add sending email function to reporting.py

In the future, except the tree closing suites, all other suites will
default to just send emails to the developers that specified in the bug
template when tests fail. Therefore, need to add sending email function
to reporting.py

BUG=chromium:525227
TEST=Test locally with fake TestBug, sent email in the expected format.

Change-Id: If9e7223bfde8924412b155d69dbb96c4145d03eb
Reviewed-on: https://chromium-review.googlesource.com/295891
Commit-Ready: Shuqian Zhao <shuqianz@chromium.org>
Tested-by: Shuqian Zhao <shuqianz@chromium.org>
Reviewed-by: Shuqian Zhao <shuqianz@chromium.org>
1 file changed