Support nose framework for the whole test suite.

--HG--
branch : trunk
diff --git a/tests/test_loaders.py b/tests/test_loaders.py
index d8f7b82..9149d46 100644
--- a/tests/test_loaders.py
+++ b/tests/test_loaders.py
@@ -7,13 +7,18 @@
     :license: BSD, see LICENSE for more details.
 """
 
-from py.test import raises
 import time
 import tempfile
 from jinja2 import Environment, loaders
 from jinja2.loaders import split_template_path
 from jinja2.exceptions import TemplateNotFound
 
+import conftest
+if conftest.NOSE:
+    from nose.tools import assert_raises as raises
+else:
+    from py.test import raises
+
 
 dict_loader = loaders.DictLoader({
     'justdict.html':        'FOO'