Swagger file generation on Spring Boot lambda

* Implementations: Spring Boot

## Scenario
I have annotated my spring boot 2 lambda with a Swagger2Config so that it auto-generates a Swagger-file for the annotated methods in the controller. Is there a way to access the swagger-ui.html after deploying the lambda? The annotated request mapping are reacheable just fine.

## Steps to reproduce
Add these maven dependencies to your spring boot 2 mvn lambda:

```

io.springfox
springfox-swagger2
2.6.1
compile

io.springfox
springfox-swagger-ui
2.6.1
compile

```
Add a Swagger2Config file and annotate the controller methods with Swagger annotations.

```
@RequestMapping(path = "/categories", method = RequestMethod.POST)
@ApiOperation(value="Add a new category",response=Category.class)
@ApiResponses(value={
@ApiResponse(code=200,message="Category created successfully",response=Category.class, responseContainer="List"),
@ApiResponse(code=500,message="Internal server error")
})
```

先檢視 issue 中描述的 Swagger2Config 與加上註解的控制器對映，接著檢查 Spring Boot 應用程式如何以 Lambda 的形式部署。確認已部署的 Lambda 是否能夠公開 swagger-ui.html，並定義可驗證的存取路徑；完成的標準是部署後可以存取 Swagger UI，或已記錄受支援的限制。

由索引模型根據 Issue 內容生成。