new: [docker-host] set system timezone

This is important for some docker, like ``cron``.

docker-host/hooks/install.d/95-timezone.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+set -eux
+
+## Timezone
+TZ=${TZ:-"Europe/Paris"}
+
+
+##
+## set system time-zone
+##
+
+printf "%s\n" "$TZ" > /etc/timezone
+dpkg-reconfigure --frontend noninteractive tzdata