Depreceate www/admin/test.php.

That page cannot test authentication sources and is therefore
deprecated.

Update issue 215
www/admin/test.php depreceated in favor of a new module which provides
the same functionality.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@1828 44740490-163a-0410-bde0-09ae8108e29a