是否有计划调整接口URL自定义v1

如Api.java类中v1/chat/completions
```
@POST("v1/chat/completions")
    Single<ChatCompletionResponse> chatCompletion(@Body ChatCompletion chatCompletion);
```

部分服务商不适配，如千帆的接口为https://qianfan.baidubce.com/v2/chat/completions/