'Create ``conf.py`` if it doesn\'t exist.'

def _write_config(self, master_doc='index'):

    docs_dir = self.docs_dir()
    conf_template = render_to_string('sphinx/conf.py.conf', {'project': self.project, 'version': self.version, 'template_dir': SPHINX_TEMPLATE_DIR, 'master_doc': master_doc})
    conf_file = os.path.join(docs_dir, 'conf.py')
    safe_write(conf_file, conf_template)
