phpunit.xml.dist referencing a non-existing XSD

[nicoschoenmaker]

If you open this file:
https://github.com/sebastianbergmann/phpunit/blob/master/phpunit.xml.dist

It references to this file:
http://phpunit.de/phpunit.xsd

This isn't the xsd though, it's being redirected to the GitHub index page.

Possible fixes:

• Ensure it works again
• Change to be https://raw.github.com/sebastianbergmann/phpunit/master/phpunit.xsd

[whatthejeff]

@sebastianbergmann, any objection to linking to the copy in the GitHub repo?