Retrieve the versions from PyPI by ``project_name``.

        Args:
            project_name (str): The name of the project we wish to retrieve
                the versions of.

        Returns:
            list: Of string versions.

def package_releases(self, project_name):
        """ Retrieve the versions from PyPI by ``project_name``.

        Args:
            project_name (str): The name of the project we wish to retrieve
                the versions of.

        Returns:
            list: Of string versions.
        """
        try:
            return self._connection.package_releases(project_name)
        except Exception as err:
            raise PyPIClientError(err)