Fixes for notebook checkpoint APIs

IPython/html/services/notebooks/filenbmanager.py

@@ -394,7 +394,7 b' class FileNotebookManager(NotebookManager):'
                 u'Notebook checkpoint does not exist: %s-%s' % (name, checkpoint_id)
             )
         # ensure notebook is readable (never restore from an unreadable notebook)
-        with file(cp_path, 'r') as f:
+        with open(cp_path, 'r') as f:
             nb = current.read(f, u'json')
         shutil.copy2(cp_path, nb_path)
         self.log.debug("copying %s -> %s", cp_path, nb_path)

IPython/html/services/notebooks/handlers.py

@@ -197,6 +197,7 b' class NotebookCheckpointsHandler(IPythonHandler):'
         location = url_path_join(self.base_project_url, u'/api/notebooks',
             path, name, 'checkpoints', checkpoint[u'checkpoint_id'])
         self.set_header(u'Location', location)
+        self.set_status(201)
         self.finish(data)