As you ran the tests, you may have seen messages warning about deprecations.
The app may pass all tests now, but the deprecations warn you of future breakages if you don't make the updates and upgrades needed.
Procedure
Make the changes suggested, and run the git_check.sh script to see if they pan out. If everything checks out, you are ready to git add/commit/push your changes and move on to the next issue.
If you need to upgrade gems, run the upgrade_gems.sh script. If everything checks out, you are ready to git add/commit/push your changes and move on to the next issue.