Realize I read the wrong documentation.

manifests/init.pp

@@ -165,18 +165,29 @@ class datorhandbok {
     ensure => directory,
   }
 
+  file { '/var/lib/mediawiki/extensions/CASAuth/':
+    ensure => link,
+    target => '/opt/CASAuth-master',
+  }
+
   archive { 'setup mediawiki CASAuth':
-    ensure           => present,
-    url              => 'https://github.com/CWRUChielLab/CASAuth/archive/master.tar.gz',
-    target           => '/var/lib/mediawiki/extensions/CASAuth/',
-    strip_components => 1,
+    ensure  => present,
+    url     => 'https://github.com/CWRUChielLab/CASAuth/archive/master.tar.gz',
+    path    => '/opt',
+    creates => '/opt/CASAuth-master',
+    extract => true,
+  }
+
+  file { '/var/lib/mediawiki/extensions/CASAuth/CAS/':
+    ensure => link,
+    target => '/opt/CAS-1.3.8',
   }
 
   archive { 'setup mediawiki CASAuth dependency':
-    ensure           => present,
-    url              => 'https://github.com/apereo/phpCAS/releases/download/1.3.8/CAS-1.3.8.tgz',
-    target           => '/var/lib/mediawiki/extensions/CASAuth/CAS/',
-    strip_components => 1,
+    ensure  => present,
+    url     => 'https://github.com/apereo/phpCAS/releases/download/1.3.8/CAS-1.3.8.tgz',
+    path    => '/opt',
+    creates => '/opt/CAS-1.3.8',
   }
 
   file { '/var/lib/mediawiki/extensions/CASAuth/CASAuthSettings.php':