add test for using docker cli

test/compose/run.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+set -e
+
+cd $(dirname $0)
+
+docker-compose up -d
+sleep 5
+
+docker-compose exec backup backup
+
+docker run --rm -it \
+  -v compose_backup_data:/data alpine \
+  ash -c 'tar -xf /data/backup/test.tar.gz && test -f /backup/app_data/offen.db'
+
+echo "[TEST:PASS] Found relevant files in untared backup."
+
+if [ "$(docker-compose ps -q | wc -l)" != "3" ]; then
+  echo "[TEST:FAIL] Expected all containers to be running post backup, instead seen:"
+  docker-compose ps
+  exit 1
+fi
+
+echo "[TEST:PASS] All containers running post backup."
+
+docker-compose down --volumes