FIX Update version in schema URL

Author: robbieaverill

src/7.0/en/configuration.xml

@@ -13,7 +13,7 @@
 
     <screen><![CDATA[<phpunit
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/6.3/phpunit.xsd"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/7.0/phpunit.xsd"
          backupGlobals="true"
          backupStaticAttributes="false"
          <!--bootstrap="/path/to/bootstrap.php"-->