Sample for Project Reactor support

[lynch19]

I would like to request a sample / feature of supporting Spring Project Reactor. If the ability exists right now, I would like an example for this.

[deki]

Hi @lynch19,
please see the discussion in #239. We have test code in https://github.com/awslabs/aws-serverless-java-container/tree/master/aws-serverless-java-container-springboot2/src/test/java/com/amazonaws/serverless/proxy/spring/webfluxapp.

I'd appreciate if someone contributes a sample by adding it to https://github.com/awslabs/aws-serverless-java-container/tree/master/samples and creating a pull request.