Move projects to better reflect the way that Spring Boot is released.
The following projects are under `spring-boot-project`:
- `spring-boot`
- `spring-boot-autoconfigure`
- `spring-boot-tools`
- `spring-boot-starters`
- `spring-boot-actuator`
- `spring-boot-actuator-autoconfigure`
- `spring-boot-test`
- `spring-boot-test-autoconfigure`
- `spring-boot-devtools`
- `spring-boot-cli`
- `spring-boot-docs`
See gh-9316
Remove test-jar artifacts from Maven projects and relocate classes. The
majority of utilities now live in the `spring-boot-testsupport` module.
This update will help us to deploy artifacts using the standard Maven
deploy plugin in the future (which doesn't support the filtering of
individual artifacts).
Fixes gh-9493