[Enhancement] TBA instructors

[Evilscaught]

Description Send out email to Cyndi if no instructor has been assigned to a class AND there are participants for that class.

• [x] Prevent hub-admin-roster email from being sent if there is no instructor
• [x] Send an email to Cyndi if no instructor has been set and there are participants
• [x] Update admin-list configuration to only include:
  • [x] Cyndi
  • [x] Dana
  • [x] Wendy
  • [x] Branden
  • [x] Amanda