Merge pull request #251 from edx/ned/pylint-fixes

cms/envs/dev.py

common/djangoapps/external_auth/views.py

common/djangoapps/heartbeat/urls.py

common/djangoapps/student/admin.py

...on/djangoapps/student/management/commands/massemailtxt.py

common/djangoapps/student/views.py

common/djangoapps/track/admin.py

common/lib/symmath/symmath/formula.py

common/lib/xmodule/xmodule/contentstore/django.py

common/lib/xmodule/xmodule/modulestore/django.py

lms/djangoapps/courseware/admin.py

lms/djangoapps/django_comment_client/helpers.py

lms/djangoapps/django_comment_client/tests.py

lms/djangoapps/django_comment_client/utils.py

...angoapps/instructor/management/commands/compute_grades.py

...angoapps/lms_migration/management/commands/create_user.py

lms/djangoapps/psychometrics/admin.py

...s/psychometrics/management/commands/init_psychometrics.py

lms/djangoapps/psychometrics/psychoanalyze.py

lms/envs/dev.py