Fix pyflakes warnings: remove unused imports and variables

tests/test_selector_events.py

@@ -1,10 +1,7 @@
 """Tests for selector_events.py"""
 
 import errno
-import gc
-import pprint
 import socket
-import sys
 import unittest
 from unittest import mock
 try:

tests/test_selectors.py

@@ -160,11 +160,11 @@ class BaseSelectorTests(unittest.TestCase):
         d2 = object()
 
         s = FakeSelector()
-        key = s.register(fobj, selectors.EVENT_READ, d1)
+        s.register(fobj, selectors.EVENT_READ, d1)
 
         s.unregister = mock.Mock()
         s.register = mock.Mock()
-        key2 = s.modify(fobj, selectors.EVENT_READ, d2)
+        s.modify(fobj, selectors.EVENT_READ, d2)
         self.assertFalse(s.unregister.called)
         self.assertFalse(s.register.called)
 

tests/test_unix_events.py

@@ -1,11 +1,9 @@
 """Tests for unix_events.py."""
 
 import collections
-import gc
 import errno
 import io
 import os
-import pprint
 import signal
 import socket
 import stat