Returns the list of signatures for which test results are saved.

    Args:
        vcs (easyci.vcs.base.Vcs)

    Returns:
        List[str]

def get_signatures_with_results(vcs):
    """Returns the list of signatures for which test results are saved.

    Args:
        vcs (easyci.vcs.base.Vcs)

    Returns:
        List[str]
    """
    results_dir = os.path.join(vcs.private_dir(), 'results')
    if not os.path.exists(results_dir):
        return []
    rel_paths = os.listdir(results_dir)
    return [p for p in rel_paths if os.path.isdir(os.path.join(results_dir, p))]