Update release note version reference table

The table indicating the openstackclient release at the time of the
overall OpenStack release had not been updated since Pike. This adds
release versions for Queens and Rocky.

Change-Id: Icd9a72c2460fae3d1b714b6da473564e6c709ef6
Signed-off-by: Sean McGinnis <sean.mcginnis@gmail.com>

Author: stmcginnis

releasenotes/source/index.rst

@@ -26,6 +26,8 @@ OpenStack release was made is shown below:
 =================  =======================
 OpenStack Release  OpenStackClient Release
 =================  =======================
+Rocky              3.16.0
+Queens             3.14.0
 Pike               3.12.0
 Ocata              3.8.1
 Newton             3.2.0