def save_report(session):
    '''
    Saves the session to a temp file, and returns that path.
    Also prunes the number of reports to 10 so there aren't loads building up.
    '''
    # prune this folder to contain the last 10 sessions
    previous_reports = glob.glob(os.path.join(report_dir(), '*.pyireport'))
    previous_reports.sort(reverse=True)
    while len(previous_reports) > 10:
        report_file = previous_reports.pop()
        os.remove(report_file)

    identifier = time.strftime('%Y-%m-%dT%H-%M-%S', time.localtime(session.start_time))

    path = os.path.join(
        report_dir(),
        identifier + '.pyireport'
    )
    session.save(path)
    return path, identifier
Saves the session to a temp file, and returns that path.
    Also prunes the number of reports to 10 so there aren't loads building up.