Creates a virtual environment for a given Django version.

        :param str dj_version:
        :rtype: str
        :return: path to created virtual env

def make_venv(self, dj_version):
        """Creates a virtual environment for a given Django version.

        :param str dj_version:
        :rtype: str
        :return: path to created virtual env
        """
        venv_path = self._get_venv_path(dj_version)
        self.logger.info('Creating virtual environment for Django %s ...' % dj_version)
        try:
            create_venv(venv_path, **VENV_CREATE_KWARGS)
        except ValueError:
            self.logger.warning('Virtual environment directory already exists. Skipped.')
        self.venv_install('django==%s' % dj_version, venv_path)
        return venv_path