@classmethod
  def unmount_persistent_disk(cls, host, keyname, is_verbose):
    try:
      remote_output = cls.ssh(host, keyname, 'umount {0}'.format(
        cls.PERSISTENT_MOUNT_POINT), is_verbose)
      AppScaleLogger.verbose(remote_output, is_verbose)
    except ShellException:
      pass
At times, Amazon hands us a timestamp with no microseconds.
dataset/ETHPy150Open AppScale/appscale-tools/lib/remote_helper.py/RemoteHelper.unmount_persistent_disk--crossover with--dataset/ETHPy150Open gtaylor/python-route53/tests/test_util.py/UtilTestCase.test_parse_iso_8601_time_str