Sets dry-run so records are not updated, only log file is produced.

def set_dry_run(xml_root, value=True):
    """Sets dry-run so records are not updated, only log file is produced."""
    value_str = str(value).lower()
    assert value_str in ("true", "false")
    if xml_root.tag == "testsuites":
        _set_property(xml_root, "polarion-dry-run", value_str)
    elif xml_root.tag in ("testcases", "requirements"):
        _set_property(xml_root, "dry-run", value_str)
    else:
        raise Dump2PolarionException(_NOT_EXPECTED_FORMAT_MSG)