add schema version to rebaseline_server intermediate JSON

NOTREECHECKS=True
NOTRY=True
R=rmistry@google.com

Author: epoger@google.com

Review URL: https://codereview.chromium.org/196343009

git-svn-id: http://skia.googlecode.com/svn/trunk@13790 2bbb7eff-a529-9590-31e7-b0007b416f81
4 files changed