Support nose framework for the whole test suite.

--HG--
branch : trunk
diff --git a/tests/test_various.py b/tests/test_various.py
index f0c997d..511b157 100644
--- a/tests/test_various.py
+++ b/tests/test_various.py
@@ -7,11 +7,16 @@
     :license: BSD, see LICENSE for more details.
 """
 import gc
-from py.test import raises
 from jinja2 import escape, is_undefined
 from jinja2.utils import Cycler
 from jinja2.exceptions import TemplateSyntaxError
 
+import conftest
+if conftest.NOSE:
+    from nose.tools import assert_raises as raises
+else:
+    from py.test import raises
+
 
 UNPACKING = '''{% for a, b, c in [[1, 2, 3]] %}{{ a }}|{{ b }}|{{ c }}{% endfor %}'''
 RAW = '''{% raw %}{{ FOO }} and {% BAR %}{% endraw %}'''