I've marked the Athena skin as unmaintained as it hasn't seen any activity in over a year and causes fatals when loaded in the current state with the current 1.35 release due to its use of include
( Warning: include(Athena.phtml): failed to open stream: No such file or directory in /Users/jrobson/git/core/skins/Athena/includes/AthenaTemplate.php on line 25)
If the skin is maintained, I'm happy to help review a patch and update the mediawiki page, but in current state we should not mislead MediaWiki users by advertising something broken as beta.