Add script to update KWIML from upstream

Utilities/Scripts/update-kwiml.bash

+#!/usr/bin/env bash
+
+set -e
+set -x
+shopt -s dotglob
+
+readonly name="KWIML"
+readonly ownership="KWIML Upstream <kwrobot@kitware.com>"
+readonly subtree="Utilities/KWIML"
+readonly repo="https://github.com/Kitware/KWIML.git"
+readonly tag="master"
+readonly shortlog=true
+readonly paths="
+"
+
+extract_source () {
+    git_archive
+}
+
+. "${BASH_SOURCE%/*}/update-third-party.bash"