Fixed #16343 -- Fixed path to the file that explains how to run the tests in the README file. Thanks, soren.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16464 bcc190cf-cafb-0310-a4f2-bffc1f526a37

README

@@ -41,7 +41,7 @@ To contribute to Django:
 To run Django's test suite:
 
     * Follow the instructions in the "Unit tests" section of
-      docs/internals/contributing.txt, published online at
+      docs/internals/contributing/writing-code/unit-tests.txt, published online at
       http://docs.djangoproject.com/en/dev/internals/contributing/#running-the-unit-tests