docs: release notes for 1.3

Change-Id: Ic974d1649859b202ecd2bd5d5eab5ffca3b8bcd8
Reviewed-on: http://gerrit.cloudera.org:8080/6334
Reviewed-by: Alexey Serbin <aserbin@cloudera.com>
Tested-by: Todd Lipcon <todd@apache.org>
(cherry picked from commit 542ba4ed78de05d78b2723bda79dda813bd7c74a)
Reviewed-on: http://gerrit.cloudera.org:8080/6341
Reviewed-by: Todd Lipcon <todd@apache.org>
3 files changed