Remove thirdparty/unittest2 from webkitpy and require python2.7.

Tools/Scripts/webkitpy/test/finder_unittest.py

 # Copyright (C) 2012 Google, Inc.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1.  Redistributions of source code must retain the above copyright
 #     notice, this list of conditions and the following disclaimer.
 # 2.  Redistributions in binary form must reproduce the above copyright
 #     notice, this list of conditions and the following disclaimer in the
 #     documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 # DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR
 # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import logging
-import webkitpy.thirdparty.unittest2 as unittest
+import unittest
 
 from webkitpy.common.system.filesystem_mock import MockFileSystem
 from webkitpy.common.system.outputcapture import OutputCapture
 from webkitpy.test.finder import Finder
 
 
 class FinderTest(unittest.TestCase):
     def setUp(self):
         files = {
           '/foo/bar/baz.py': '',
@@ skipping 82 matching lines @@
         # Paths that don't exist are errors.
         oc.capture_output()
         try:
             self.check_names(['/foo/bar/notexist_unittest.py'], [])
         finally:
             _, _, logs = oc.restore_output()
             self.assertIn('notexist_unittest.py', logs)
 
         # Names that don't exist are caught later, at load time.
         self.check_names(['bar.notexist_unittest'], ['bar.notexist_unittest'])