Add PHPUnit to About page

assets/javascripts/templates/pages/about_tmpl.coffee

@@ -232,6 +232,11 @@ credits = [
     '1997-2014 The PHP Documentation Group',
     'CC BY',
     'http://creativecommons.org/licenses/by/3.0/'
+  ], [
+    'PHPUnit',
+    '2005-2014 Sebastian Bergmann',
+    'CC BY',
+    'http://creativecommons.org/licenses/by/3.0/'
   ], [
     'PostgreSQL',
     '1996-2013 The PostgreSQL Global Development Group<br>&copy; 1994 The Regents of the University of California',