Return a human-friendly URL for this product.

        :param product: str, eg. "ceph"
        :returns: str, URL

def product_url(self, product):
        """
        Return a human-friendly URL for this product.

        :param product: str, eg. "ceph"
        :returns: str, URL
        """
        url = 'product/%s' % product
        return posixpath.join(self.url, url)