Make it possible to consume Spring Boot Actuator hypermedia

[gregturn]

Consuming Spring Boot Actuator’s hypermedia should be easy. Check if Boot is serving up the right media type and then verify we can consume it with:

• RestTemplate
• WebClient
• Traverson

NOTE: Recommend label “integration”.

[gregturn]

Inspired by #1050 but we should target Boot 2.2.