initial commit for adding members
sending email
inviting single email addresses done
adding users via CSV -> celery task
include username in existing user invite email
added preenroll_only functionality
class member promote/demote
NO-OP change to retry travis (tests pass locally)
192 char email field -> 128 char
user settings.SERVER_EMAIL instead of hardcode
Merge pull request #2343 from Stanford-Online/jbau-member-management

Jbau member management