PEP8 cleanups

mayan/apps/authentication/forms.py

@@ -1,14 +1,9 @@
 from __future__ import unicode_literals
 
 import warnings
-import os
 
 from django import forms
-from django.conf import settings
 from django.contrib.auth import authenticate
-from django.contrib.auth.models import User
-from django.db import models
-from django.utils.html import escape
 from django.utils.translation import ugettext_lazy as _
 
 from common.widgets import EmailInput