Establish a pattern for a unit testing quality gate for components

[davgordo]

We can use a simple Spring Boot example as a starting point here:
https://github.com/contract-first-idp/java-unit-test-prototype

We can assume Java+Maven. Jacoco should likely be the coverage report tool, but open to other options.

Acceptance criteria:

• develop a Java service prototype pipeline with a step that executes unit tests
• configure code coverage to be generated when unit tests are executed
• pass/fail tekton build based on meeting coverage ratio minimum requirement (suggestion: 60%)