Write CSV file with versions used in analysis pipeline.

def write_versions(dirs, config=None, is_wrapper=False):
    """Write CSV file with versions used in analysis pipeline.
    """
    out_file = _get_program_file(dirs)
    if is_wrapper:
        assert utils.file_exists(out_file), "Failed to create program versions from VM"
    elif out_file is None:
        for p in _get_versions(config):
            print("{program},{version}".format(**p))
    else:
        with open(out_file, "w") as out_handle:
            for p in _get_versions(config):
                out_handle.write("{program},{version}\n".format(**p))
    return out_file