Add script for update all docker images

Signed-off-by: Alice Ferrazzi <alicef@gentoo.org>

Author: aliceinwire

update-images.sh

@@ -0,0 +1,7 @@
+#!/bin/env bash
+docker pull buildbot/buildbot-master:master
+docker pull buildbot/buildbot-worker:master
+docker pull nginxproxy/nginx-proxy:alpine
+docker pull ubuntu:bionic
+docker pull nginx:stable-alpine
+docker-compose pull --include-deps