issue #477: remove unused pytest bits from importer_test.

tests/importer_test.py

@@ -1,12 +1,10 @@
 
-import email.utils
 import sys
 import threading
 import types
 import zlib
 
 import mock
-import pytest
 import unittest2
 
 import mitogen.core
@@ -144,7 +142,6 @@ class LoadModulePackageTest(ImporterMixin, testlib.TestCase):
 
 
 class EmailParseAddrSysTest(testlib.RouterMixin, testlib.TestCase):
-    @pytest.fixture(autouse=True)
     def initdir(self, caplog):
         self.caplog = caplog