chore: various tweaks to support running tests in the CI

docker-compose.yml

@@ -0,0 +1,29 @@
+version: "3"
+services:
+  postal:
+    image: ${POSTAL_IMAGE}
+    depends_on:
+      - mariadb
+      - rabbitmq
+    entrypoint: ["/docker-entrypoint.sh"]
+    volumes:
+      - "./docker/ci-config:/config"
+    environment:
+      POSTAL_CONFIG_ROOT: /config
+      KATAPULT_CONFIG_FILE: /ci-config.yml
+      WAIT_FOR_TIMEOUT: 90
+      WAIT_FOR_TARGETS: |-
+        mariadb:3306
+        rabbitmq:5672
+
+  mariadb:
+    image: mariadb
+    restart: always
+    environment:
+      MARIADB_DATABASE: postal
+      MARIADB_ALLOW_EMPTY_PASSWORD: 'yes'
+      MARIADB_ALLOW_EMPTY_ROOT_PASSWORD: 'yes'
+
+  rabbitmq:
+    image: rabbitmq:3
+    restart: always