Fix environment save/restore error in test. Reviewed in http://codereview.appspot.com/5083041
diff --git a/tests/test_discovery.py b/tests/test_discovery.py
index 71ca0fb..b5ac753 100644
--- a/tests/test_discovery.py
+++ b/tests/test_discovery.py
@@ -23,7 +23,6 @@
 
 __author__ = 'jcgregorio@google.com (Joe Gregorio)'
 
-import copy
 import httplib2
 import os
 import unittest
@@ -85,7 +84,7 @@
 
 class DiscoveryFromHttp(unittest.TestCase):
   def setUp(self):
-    self.old_environ = copy.copy(os.environ)
+    self.old_environ = os.environ.copy()
 
   def tearDown(self):
     os.environ = self.old_environ