Fix failing test case on Windows (can't rmtree if a file is open in that tree)

--HG--
branch : distribute
extra : rebase_source : 99e78b88c18007b410c0be28237db8341413e334

setuptools/tests/test_upload_docs.py

@@ -65,6 +65,8 @@ class TestUploadDocsTest(unittest.TestCase):
             zip_file = zipfile.ZipFile(tmp_file) # woh...
 
             assert zip_file.namelist() == ['index.html']
+
+            zip_file.close()
         finally:
             shutil.rmtree(tmp_dir)