Remove all recordings which have points without time.
    Parameters
    ----------
    recordings : list of dicts
        Each dictionary has the keys 'data' and 'segmentation'

    Returns
    -------
    list of dicts :
        Only recordings where all points have time values.

def filter_recordings(recordings):
    """Remove all recordings which have points without time.
    Parameters
    ----------
    recordings : list of dicts
        Each dictionary has the keys 'data' and 'segmentation'

    Returns
    -------
    list of dicts :
        Only recordings where all points have time values.
    """
    new_recordings = []
    for recording in recordings:
        recording['data'] = json.loads(recording['data'])
        tmp = json.loads(recording['segmentation'])
        recording['segmentation'] = normalize_segmentation(tmp)
        had_none = False
        for stroke in recording['data']:
            for point in stroke:
                if point['time'] is None:
                    logging.debug("Had None-time: %i", recording['id'])
                    had_none = True
                    break
            if had_none:
                break
        if not had_none:
            new_recordings.append(recording)

    recordings = new_recordings
    logging.info("Done filtering")
    return recordings