bug symfony#4292 Fixed broken external link to DemoController Test (danielsan)

This PR was submitted for the 2.5 branch but it was merged into the 2.3 branch instead (closes symfony#4292).

Discussion
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Fixed broken external link to DemoController Test

Commits
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6cba2db Fixed broken external link to DemoController Test

Author: wouterj

book/testing.rst

@@ -852,6 +852,6 @@ Learn more
 * :doc:`/cookbook/testing/profiling`
 * :doc:`/cookbook/testing/bootstrap`
 
-.. _`DemoControllerTest`: https://github.com/symfony/symfony-standard/blob/master/src/Acme/DemoBundle/Tests/Controller/DemoControllerTest.php
+.. _`DemoControllerTest`: https://github.com/sensiolabs/SensioDistributionBundle/blob/master/Resources/skeleton/acme-demo-bundle/Acme/DemoBundle/Tests/Controller/DemoControllerTest.php
 .. _`$_SERVER`: http://php.net/manual/en/reserved.variables.server.php
 .. _`documentation`: http://phpunit.de/manual/current/en/