def get_creds(filename):
    """
    Read credentials from a file. Format is:
    URL
    USERNAME
    PASSWORD

    Parameters
    ----------
    filename: string
        path to the file with the credentials

    Returns
    -------
    list as [URL, USERNAME, PASSWORD]
    """
    f = open(filename, "r")
    lines = f.readlines()
    if len(lines) != 3:
        raise ValueError("Not a valid credentials file.")
    # strip out newline chars
    content = [x.rstrip() for x in lines]
    return content