Separate Organizers (admins) from Participants

[Muirrum]

Administrators should not be included in the participant count

[ngolp]

I addressed this issue in the branch "separate-users-admins" (https://github.com/wpi-acm/Hack-WPI-Python/tree/separate-users-admins).

I didn't know if I was supposed also to change the /mail route as shown below. Feel free to change it back!

[Muirrum]

Please do!