Remove some unnecessary imports

IPython/html/services/notebooks/filenbmanager.py

@@ -21,7 +21,6 b' import io'
 import os
 import glob
 import shutil
-import ast
 
 from unicodedata import normalize
 

IPython/html/services/notebooks/handlers.py

@@ -17,7 +17,6 b' Authors:'
 #-----------------------------------------------------------------------------
 
 from tornado import web
-import ast
 
 from zmq.utils import jsonapi