Create release/build notes generator

The build process already does provide some diff of packages https://logs.akraino.org/production/vex-yul-akraino-jenkins-prod-1/ta-ci-build/52/packages_diff.txt.gz but it is difficult to really understand what has changed between builds. As we move from daily to on-demand it is even more important to have an easy way to see what has changed.

This story is to build a tool that uses Git logs of the TA repos https://gerrit.akraino.org/r/#/admin/projects/?filter=ta%252F to generate a summary of changes in the REC builds: https://nexus.akraino.org/content/repositories/images-snapshots/TA/release-1/images/

Initial implementation may simply be to generate a text file in each directory with the ISO files (for example https://nexus.akraino.org/content/repositories/images-snapshots/TA/release-1/images/55/ ) but an eventual target should be to be able to generate a summary of the difference between any two builds.

Additional enhancement may or may not be needed to generate a summary of differences between releases. Since every release will be some build (e.g. Release 1 was build 9 https://nexus.akraino.org/content/repositories/images-snapshots/TA/release-1/images/9/ ) it might be sufficient to use the functionality requested above to generate a comprehensive list of changes between build 9 and whatever build gets designated as Release 2. However, it might be possible to do something more for release notes.