Read a .env file and load into os.environ.

    :param dotenv_path:
    :type dotenv_path: str
    :param verbose: verbosity flag, raise warning if path does not exist
    :return: success flag

def load_dotenv(dotenv_path, verbose=False):
    """
    Read a .env file and load into os.environ.

    :param dotenv_path:
    :type dotenv_path: str
    :param verbose: verbosity flag, raise warning if path does not exist
    :return: success flag
    """
    if not os.path.exists(dotenv_path):
        if verbose:
            warnings.warn(f"Not loading {dotenv_path}, it doesn't exist.")
        return None
    for k, v in dotenv_values(dotenv_path).items():
        os.environ.setdefault(k, v)
    return True