MB-100: updated CHANGELOG

Change-Id: I76f37312b1c79a6f197c243d6787ba9ec536bb31
Reviewed-on: http://review.couchbase.org/24073
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>