Point to information on how to run the test suite. (closes symfony#5405)

Author: sebastianbergmann

README.md

@@ -50,8 +50,15 @@ Symfony2 is an open source, community-driven project. If you'd like to contribut
 please read the [Contributing Code][4] part of the documentation. If you're submitting
 a pull request, please follow the guidelines in the [Submitting a Patch][5] section.
 
+Running Symfony2 Tests
+----------------------
+
+Information on how to run the Symfony2 test suite can be found in the
+[Running Symfony2 Tests][6] section.
+
 [1]: http://symfony.com/download
 [2]: http://symfony.com/get_started
 [3]: http://symfony.com/doc/current/
 [4]: http://symfony.com/doc/current/contributing/code/index.html
 [5]: http://symfony.com/doc/current/contributing/code/patches.html#check-list
+[6]: http://symfony.com/doc/master/contributing/code/tests.html