Bump "tested up to" version.

Author: Michael Sisk

readme.txt

@@ -3,7 +3,7 @@ Contributors: mgsisk
 Donate link: http://webcomic.nu
 Tags: webcomics, comics, multiple comics, storylines, characters, custom post type, custom taxonomy, template tags, shortcodes, widgets, twitter, facebook, open graph
 Requires at least: 3.5
-Tested up to: 3.8
+Tested up to: 3.8.1
 Stable tag: 4.1.0.4
 License: GPL3
 License URI: http://www.gnu.org/licenses/gpl.html