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")
})
```

Start by reviewing the Swagger2Config and the annotated controller mappings described in the issue, then inspect how the Spring Boot application is deployed as a Lambda. Determine whether the deployed Lambda can expose swagger-ui.html and define a verifiable access path; done means the Swagger UI is reachable after deployment or the supported limitation is documented.

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