automate consistency checks

[hboutemy]

when we add or archive a component, we often forget one of the following:

• repo's default.xml
• README.md
• aggregator build
• dist tool https://ci-maven.apache.org/job/Maven/job/maven-box/job/maven-dist-tool/job/master/site/index.html
• sources list https://maven.apache.org/scm.html