Bump copyright year to year of latest release #5
It's good to have the copyright year on par with the most recent release year and this PR implements that change. I've noticed that sometimes ranges are used and sometimes not. In each case I've simply updated the most recent year; leaving ranges as-is and not creating a range if one wasn't already present. If you would specifically like ranges for all copyright years, I can update the PR appropriately and resubmit.