[webrtc-stats] Pull Request: Change log, and make tidy

alvestrand has just submitted a new pull request for https://github.com/w3c/webrtc-stats:

== Change log, and make tidy ==
Note that "make tidy" inserts an extra space for reasons unknown.
It is too tedious to remove it by hand, so it's left in.

See https://github.com/w3c/webrtc-stats/pull/186