Give an url a score which can be used to choose preferred URLs
        for a given project release.

def score_url(self, url):
        """
        Give an url a score which can be used to choose preferred URLs
        for a given project release.
        """
        t = urlparse(url)
        return (t.scheme != 'https', 'pypi.python.org' in t.netloc,
                posixpath.basename(t.path))