Merge pull request #459 from edx/gprice/notification-setting-endpoints

CHANGELOG.rst

common/djangoapps/terrain/steps.py

lms/djangoapps/notification_prefs/__init__.py

...jangoapps/notification_prefs/features/unsubscribe.feature

lms/djangoapps/notification_prefs/features/unsubscribe.py

lms/djangoapps/notification_prefs/tests.py

lms/djangoapps/notification_prefs/views.py

lms/envs/acceptance.py

lms/envs/common.py

lms/static/sass/application.scss.mako

lms/static/sass/shared/_unsubscribe.scss

lms/templates/unsubscribe.html

lms/urls.py

requirements/edx/base.txt