Creates a namespace in the triplestore

        args:
            namespace: the name of the namspace to create
            params: Dictionary of Blazegraph paramaters. defaults are:

                    {'axioms': 'com.bigdata.rdf.axioms.NoAxioms',
                     'geoSpatial': False,
                     'isolatableIndices': False,
                     'justify': False,
                     'quads': False,
                     'rdr': False,
                     'textIndex': False,
                     'truthMaintenance': False}

def create_namespace(self, namespace=None, params=None):
        """ Creates a namespace in the triplestore

        args:
            namespace: the name of the namspace to create
            params: Dictionary of Blazegraph paramaters. defaults are:

                    {'axioms': 'com.bigdata.rdf.axioms.NoAxioms',
                     'geoSpatial': False,
                     'isolatableIndices': False,
                     'justify': False,
                     'quads': False,
                     'rdr': False,
                     'textIndex': False,
                     'truthMaintenance': False}
        """
        namespace = pick(namespace, self.namespace)
        params = pick(params, self.namespace_params)
        if not namespace:
            raise ReferenceError("No 'namespace' specified")
        _params = {'axioms': 'com.bigdata.rdf.axioms.NoAxioms',
                   'geoSpatial': False,
                   'isolatableIndices': False,
                   'justify': False,
                   'namespace': namespace,
                   'quads': True,
                   'rdr': False,
                   'textIndex': False,
                   'truthMaintenance': False}
        if params:
            _params.update(params)
        content_type = "text/plain"
        url = self._make_url("prepareProperties").replace("/sparql", "")
        params = ["%s=%s" % (map_val,
                             json.dumps(_params[map_key]).replace("\"", "")) \
                  for map_key, map_val in self.ns_property_map.items()]
        params = "\n".join(params)
        result = requests.post(url=url,
                               headers={"Content-Type": content_type},
                               data=params)
        data = result.text
        content_type = "application/xml"
        url = self._make_url("x").replace("/x/sparql", "")
        result = requests.post(url=url,
                               headers={"Content-Type": content_type},
                               data=data)
        if result.status_code == 201:
            log.warning(result.text)
            return result.text
        else:
            raise RuntimeError(result.text)