Update README.

Run the test suite with "python setup.py test".

From: Fabian Pedregosa <fabian.pedregosa@inria.fr>

git-svn-id: https://scikit-learn.svn.sourceforge.net/svnroot/scikit-learn/trunk@391 22fbfee3-77ab-4535-9bad-27d1bd3bc7d8

README

@@ -84,8 +84,9 @@ https://sourceforge.net/apps/trac/scikit-learn/report
 Testing
 -------
 
-To execute the test suite, run from the project's top directory::
+To execute the test suite, run from the project's top directory (you
+will need to have nosetest installed)::
 
-    nosetests --with-doctest scikits/
+    python setup.py test