address some violations

common/djangoapps/util/forum_util.py

-from django_comment_client.models import Permission, Role
+from django_comment_client.models import Role
+
 
 def seed_permissions_roles(course_id):
     administrator_role = Role.objects.get_or_create(name="Administrator", course_id=course_id)[0]
@@ -7,12 +8,12 @@ def seed_permissions_roles(course_id):
     student_role = Role.objects.get_or_create(name="Student", course_id=course_id)[0]
 
     for per in ["vote", "update_thread", "follow_thread", "unfollow_thread",
-                   "update_comment", "create_sub_comment", "unvote", "create_thread",
-                   "follow_commentable", "unfollow_commentable", "create_comment", ]:
+                "update_comment", "create_sub_comment", "unvote", "create_thread",
+                "follow_commentable", "unfollow_commentable", "create_comment", ]:
         student_role.add_permission(per)
 
     for per in ["edit_content", "delete_thread", "openclose_thread",
-                    "endorse_comment", "delete_comment", "see_all_cohorts"]:
+                "endorse_comment", "delete_comment", "see_all_cohorts"]:
         moderator_role.add_permission(per)
 
     for per in ["manage_moderator"]:
@@ -23,4 +24,4 @@ def seed_permissions_roles(course_id):
     # For now, Community TA == Moderator, except for the styling.
     community_ta_role.inherit_permissions(moderator_role)
 
-    administrator_role.inherit_permissions(moderator_role)
\ No newline at end of file
+    administrator_role.inherit_permissions(moderator_role)

common/lib/xmodule/xmodule/raw_module.py

 from lxml import etree
-from xmodule.editing_module import XMLEditingDescriptor, MetadataOnlyEditingDescriptor
+from xmodule.editing_module import XMLEditingDescriptor
 from xmodule.xml_module import XmlDescriptor
 import logging
 import sys
@@ -29,6 +29,6 @@ class RawDescriptor(XmlDescriptor, XMLEditingDescriptor):
             line, offset = err.position
             msg = ("Unable to create xml for problem {loc}. "
                    "Context: '{context}'".format(
-                    context=lines[line - 1][offset - 40:offset + 40],
-                    loc=self.location))
+                   context=lines[line - 1][offset - 40:offset + 40],
+                   loc=self.location))
             raise Exception, msg, sys.exc_info()[2]