Return the substitutions for the templating replacements.

def substitutes(self):
        """ Return the substitutions for the templating replacements. """
        author_collector = AuthorCollector()
        mail_collector = AuthorMailCollector()
        substitute_dict = dict(
            project = self.project_name,
            project_lower = self.project_name.lower(),
            date = date.today().isoformat(),
            author = author_collector.collect(),
            author_email = mail_collector.collect(),
        )
        return substitute_dict