Add support for the ReactiveDiscoveryClient

[joshiste]

https://spring.io/blog/2019/10/05/spring-cloud-hoxton-m3-is-now-available

[joshiste]

@duanhairuo I don't grok your question.

[mdeverdelhan]

@duanhairuo Not yet. See https://github.com/codecentric/spring-boot-admin/releases
I hope it will occur soon.

[patpatpat123]

Ilford is about to be out!

[joshiste]

When nothing has changed in between there is always a non-reactive version for the discovery implementations available. So this is more a nice to have.