[docs] Add 1.16.0 release notes to previous release notes

Change-Id: I20a3de90d774f40aec4e03b810e55b72bff27fd1
Reviewed-on: http://gerrit.cloudera.org:8080/20296
Tested-by: Kudu Jenkins
Reviewed-by: Alexey Serbin <alexey@apache.org>
(cherry picked from commit 956f2028bda9f4f67573d9bbe8c27388d5595393)
Reviewed-on: http://gerrit.cloudera.org:8080/20298
1 file changed