ci: standalone compose file for proxy-host-network-mode

This is to prevent the below error with docker-compose v1:

ERROR: for nginx-proxy  "host" network_mode is incompatible with port_bindings

test/test_host-network-mode/test_proxy-host-network-mode.base.yml

@@ -0,0 +1,25 @@
+services:
+  nginx-proxy:
+    image: nginxproxy/nginx-proxy:test
+    container_name: nginx-proxy
+    volumes:
+      - /var/run/docker.sock:/tmp/docker.sock:ro
+    environment:
+      HTTP_PORT: 8888
+    network_mode: host
+
+  host-network-1:
+    image: web
+    environment:
+      WEB_PORTS: "8080"
+      VIRTUAL_HOST: "host-network-1.nginx-proxy.tld"
+      VIRTUAL_PORT: "8080"
+    network_mode: host
+
+  host-network-2:
+    image: web
+    environment:
+      WEB_PORTS: "8181"
+      VIRTUAL_HOST: "host-network-2.nginx-proxy.tld"
+      VIRTUAL_PORT: "8181"
+    network_mode: host