Fixes following code review

theano/misc/tests/test_pkl_utils.py

-import numpy
-from numpy.testing import assert_allclose
-from nose.plugins.skip import SkipTest
 import os
-from tempfile import mkdtemp
 import shutil
 import unittest
+from tempfile import mkdtemp
+
+import numpy
+from numpy.testing import assert_allclose
+from nose.plugins.skip import SkipTest
 
 import theano
 import theano.sandbox.cuda as cuda_ndarray
@@ -19,7 +20,6 @@ class T_dump_load(unittest.TestCase):
     def setUp(self):
         # Work in a temporary directory to avoid cluttering the repository
         self.origdir = os.getcwd()
-        self.tmpdir = None
         self.tmpdir = mkdtemp()
         os.chdir(self.tmpdir)