Produces an s3 url for a given blueprint.

    Args:
        bucket_name (string): The name of the S3 bucket where the resulting
            templates are stored.
        blueprint (:class:`stacker.blueprints.base.Blueprint`): The blueprint
            object to create the URL to.
        endpoint (string): The s3 endpoint used for the bucket.

    Returns:
        string: S3 URL.

def stack_template_url(bucket_name, blueprint, endpoint):
    """Produces an s3 url for a given blueprint.

    Args:
        bucket_name (string): The name of the S3 bucket where the resulting
            templates are stored.
        blueprint (:class:`stacker.blueprints.base.Blueprint`): The blueprint
            object to create the URL to.
        endpoint (string): The s3 endpoint used for the bucket.

    Returns:
        string: S3 URL.
    """
    key_name = stack_template_key_name(blueprint)
    return "%s/%s/%s" % (endpoint, bucket_name, key_name)