1.3.2 Release

Please reply to this email if you have pending patches to be backported to 1.3.x, I'm aiming to cut a 1.3.2 on Friday. Thanks, MPark

clearing the executor authentication token from the task environment

Hi all, In https://issues.apache.org/jira/browse/MESOS-8140, I'm proposing that we clear the MESOS_EXECUTOR_AUTHENTICATION_TOKEN environment variable immediately after consuming it in the built-in executors. This protects it from observation by other tasks in the same PID namespace, however I w