Create a new :class:`CustomAttribute`.

        :param project: :class:`Project` id
        :param name: name of the custom attribute
        :param attrs: optional attributes of the custom attributes

def create(self, project, name, **attrs):
        """
        Create a new :class:`CustomAttribute`.

        :param project: :class:`Project` id
        :param name: name of the custom attribute
        :param attrs: optional attributes of the custom attributes
        """
        attrs.update(
            {
                'project': project, 'name': name
            }
        )
        return self._new_resource(payload=attrs)