Provide autocompletable @ConfigurationProperties for registry configs

[jkschneider]

From #68:

As we are at it, is it feasible to integrate the spring-boot-configuration-processor so that any @ConfigurationProperties are autocompletable in application.yml where there is IDE support?

cc / @mweirauch

[mweirauch]

Since 'metrics-spring' has vaporized with 0c23dc8 the only place to add would be for 'metrics-spring-legacy', right?
What is happening to Spring 5 and Spring Boot 2 support? Some place to read about the bigger plans?

[jkschneider]

A PR is open in Spring Boot 2 where we plan to incorporate Micrometer out-of-the-box.

I'm working on this issue and #96 right now, and will update the Boot 2 PR when complete.

We'll put out a blog post on the big picture on the Spring blog in about 2 weeks when Spring Boot M4 and the first 1.0 milestone of Micrometer land.