config.yml.liquid

```
{% include 'query' %}

{% include 'conn' %}

out: {type: stdout}
```

_conn.yml.liquid

```yaml
in:
  type: postgresql
  host: 127.0.0.1
  user: user
  password: password
  database: embulk_test
  query: *test
```

_query.yml.liquid

```yaml
query: &test "select * from auto_inc_test"
```