Log auto-rebaseline to blinkrebaseline.appspot.com so people can see the progress of their rebaselines.

This isn't perfect. It doesn't log everything, so, it doesn't replace saving the logs
locally for debugging when things go wrong. But it's enough that people can see
the bot working and not have to wonder if it's even running.

Review URL: https://chromiumcodereview.appspot.com/22075002

git-svn-id: svn://svn.chromium.org/blink/trunk@155977 bbb929c8-8fbe-4397-9dbb-9b2b20218538