Fix rubocop error for the constant by converting to uppercase

This PR fixes the rubocop issue of the Constant Name for the exercise concept of port-palermo. Since usage of uppercase constants are recommended by the rubocop docs and it is a good practice.

Well, since my https://forum.exercism.org account was on hold I thought OK probably this PR will never merge and I don’t know how long my account will be on hold so I decided that I would just delete the branch. Now, it I understand that it was a bad idea, sorry lol :) you guys are faster than I thought.

If you think the changes in this PR are relevant and okay, I might just open another one. I can’t restore this one. What would you say?

Review what was said on that pull request that was closed.

I think there is a “contributors” section to put your information in, as opposed to “author”.

And I think it is OK for the most part.

But yes, when it is time, you will most likely have to, unless you can recreate that branch. (not sure how github works those, exactly, so that may not be possible.)

Thanks for the fast response on the new PR.