add a warning in network mode test about macos

Author: jarlah

test/generic_container_test.exs

@@ -13,6 +13,9 @@ defmodule Testcontainers.GenericContainerTest do
     config = %Testcontainers.Container{image: "redis:latest", network_mode: "host"}
     assert {:ok, container} = Testcontainers.start_container(config)
     Process.sleep(5000)
+    with {:unix, :darwin} <- :os.type() do
+      IO.puts("Testing network_mode=host doesn't work in macos!")
+    end
     assert :ok = port_open?("127.0.0.1", 6379)
     assert :ok = Testcontainers.stop_container(container.container_id)
   end