Update year

Author: RichardLitt

_includes/footer.html

@@ -78,7 +78,7 @@
   <div class="footer-bottom py-4 text-center">
     <div class="container">
       <div class="copyright">
-        © 2016-{{ site.time | date: '%Y' }}
+        © {{ site.time | date: '%Y' }}
         SustainOSS.org - Unless otherwise noted, content on this site is licensed under a <a href="https://creativecommons.org/licenses/by-sa/4.0/" rel="noopener" target="_blank">CC-BY-SA 4.0 License</a>
       </div>
       <div class="mt-3">