* Some dependencies upgrades
* This PR is also for trying GH Actions in action
* * Fix `pr-build-workflow.yml` trailing whitespaces and indents
* Fix Checkstyle upgrade compatibility
* Fix Checkstyle violations in the code
* * Remove `.travis.yml`
* Fix `updateCopyrights` task to rely on the `GITHUB_ACTION` env var now
* Add `distributionSha256Sum` into `gradle-wrapper.properties` as it is recommended by GH Actions