get rid of unused imports

lib/python/Products/PageTemplates/tests/testDTMLTests.py

@@ -11,7 +11,7 @@
 #
 ##############################################################################
 
-import os, sys, unittest
+import unittest
 
 import zope.component.testing
 from zope.traversing.adapters import DefaultTraversable

lib/python/Products/PageTemplates/tests/testExpressions.py

-import os, sys, unittest
+import unittest
 
 from Products.PageTemplates import Expressions
 from Products.PageTemplates.DeferExpr import LazyWrapper

lib/python/Products/PageTemplates/tests/testHTMLTests.py

@@ -11,7 +11,7 @@
 #
 ##############################################################################
 
-import os, sys, unittest
+import unittest
 
 import zope.component.testing
 from zope.traversing.adapters import DefaultTraversable

lib/python/Products/PageTemplates/tests/testTALES.py

-import os, sys, unittest
+import unittest
 
 from Products.PageTemplates import TALES
 from zope.tales.tests.test_tales import Harness
-import string
 
 class DummyUnicodeExpr:
     '''Dummy expression type handler returning unicode'''