message: Remove dependency on pathlib and workaround it by using six.moves.urllib_parse
diff: @@ -17,7 +17,6 @@ from __future__ import division
  from __future__ import print_function
  import os
  -import pathlib
  import tempfile
  import time
  @@ -280,7 +279,7 @@ class EagerDbTest(summary_test_util.SummaryDbTest):
  def testDbURIOpen(self):
  tmpdb_path = os.path.join(self.get_temp_dir(), 'tmpDbURITest.sqlite')
  - tmpdb_uri = pathlib.Path(tmpdb_path).as_uri()
  + tmpdb_uri = six.moves.urllib_parse.urljoin("file:", tmpdb_path)
  tmpdb_writer = summary_ops.create_db_writer(
  tmpdb_uri,
  "experimentA",
  