Some Fixes for pylint

mfa/U2F.py

@@ -10,14 +10,12 @@ from cryptography.hazmat.primitives.serialization import Encoding
 from django.shortcuts import render
 import simplejson
 
-# from django.template.context import RequestContext
 from django.template.context_processors import csrf
-from django.conf import settings
 from django.http import HttpResponse
-from .models import *
+from django.conf import settings
+from .models import User_Keys
 from .views import login
 from .Common import get_redirect_url
-import datetime
 from django.utils import timezone