Added bill of materials

[whiskeysierra]

Description

Logbook has already 5+ modules that produce individual artifacts. Users that depend on them will usually list them all as dependencies in their POMs. Right now we guarantee that version numbers across modules are always the same, i.e. a new release will release each module, even if it wasn't change.
That allows users right now already to use a single maven property logbook.version that is used for each dependency.

This pull requests introduces a BOM (bill of material) as an alternative. The BOM can be imported in the dependencyManagement section of a POM.

Motivation and Context

The BOM removes the need to specify any version on individual logbook artifacts.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[lukasniemeier-zalando]

👍

[rainermueller]

To omit the versions in pom.xml the dependencies in org.zalando:logbook-bom must define <version>${logbook.version}</version>

We still have to define the dependency version due to following error

[ERROR] 'dependencies.dependency.version' for org.zalando:logbook-servlet:jar is missing. @ com.inventage.demo:backend-war:[unknown-version]

[whiskeysierra]

Shouldn't the version be inherited from the parent?

[rainermueller]

Compared to org.springframework:spring-framework-bom and others every dependency defines the version.

[whiskeysierra]

Would you mind creating a pull request?

[rainermueller]

Done, see Update bill of materials (BOM) to define version for each dependency