[telemetry] Sort imports in Telemetry and its dependents.

tools/telemetry/telemetry/value/trace_unittest.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os
-import unittest
 import shutil
 import tempfile
+import unittest
 
 from telemetry import page as page_module
 from telemetry.page import page_set
 from telemetry.timeline import trace_data
 from telemetry.unittest_util import system_stub
 from telemetry.util import file_handle
 from telemetry.value import trace
 
 
 class TestBase(unittest.TestCase):
@@ skipping 94 matching lines @@
 
   def testNoLeakedTempFileWhenUploadingTrace(self):
     v = trace.TraceValue(None, trace_data.TraceData({'test': 1}))
     v.CleanUp()
     self.assertTrue(_IsEmptyDir(self.temp_test_dir))
 
   def tearDown(self):
     super(NoLeakedTempfilesTests, self).tearDown()
     shutil.rmtree(self.temp_test_dir)
     trace.tempfile.tempdir = self.actual_tempdir