adding certs role
moves discern over to celery, creates some deploy plays
Merge pull request #408 from edx/jarv/edxapp-cleanup-and-certs

Some general cleanup of the edxapp role, adding certs to continuous integration
Merge remote-tracking branch 'origin' into jarv/discern-supervisor
Merge pull request #410 from edx/jarv/discern-supervisor

Jarv/discern supervisor
fixing handler name
Merge pull request #411 from edx/jarv/fix-handler-name

fixing handler name
edxapp-extra-vars: Expose extra variables for configuration of the edxapp role
Stanford datadog playbook updates
Merge pull request #415 from edx/jrbl/stanford/playbook-updates

Stanford datadog playbook updates
fixing directory perms for discern
Merge pull request #416 from edx/jarv/fix-discern-perms

fixing directory perms for discern
this adds some sample users using the new create_user django-admin.py
command
Merge pull request #417 from edx/jarv/add-test-users

this adds some sample users using the new create_user django-admin.py
Merge pull request #413 from BitFountain/edxapp-extra-vars

edxapp-extra-vars: Expose extra variables for configuration of the edxapp role
fixing discern settings for discern_celery
Merge pull request #418 from edx/jarv/fix-discern-settings

fixing discern settings for discern_celery
Add default emails that can be overridden.
Update to prefix edxapp and remove settings that already existed.
Merge pull request #419 from edx/feanil/default_emails

Feanil/default emails