Add docker software to allow using dind enabled images

scripts/install-docker

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+set -xeuo pipefail
+
+export DEBIAN_FRONTEND=noninteractive
+
+DOCKER_VERSION=${1}
+
+apt-get -y install \
+    apt-transport-https \
+    ca-certificates \
+    curl \
+    gnupg
+
+curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add -
+
+
+echo "deb [arch=amd64] https://download.docker.com/linux/debian stretch stable" >> /etc/apt/sources.list.d/docker.list
+apt-get update
+
+PACKAGE_VERSION=$(apt-cache policy docker-ce | awk -v dv=${DOCKER_VERSION} '$1 ~ dv {print $1}')
+
+apt-get install -y docker-ce=${PACKAGE_VERSION}
+apt-get -yq autoremove
+apt-get clean -yqq
+rm -rf /var/lib/apt/lists/*