Add inactive member roles

[DaAwesomeP]

I would like to add the following roles:

• Inactive Student: For current students who have not been at all in contact or active with Tech in some time. This should place them in a new category in the run crew assignment dropdown between active members and alumni. This role should not have any more permissions than a not logged-in viewer.
• Advisor: This is for SLICE advisors. I believe they should have the same view permissions as Exec but no edit permissions. I am not completely familiar with all of the permissions, so let me know if you think they should be able to see more
• Inactive Alumni: Or maybe it should be called Graduated Inactive Student. This role needs some discussion. This is not for alumni who have become inactive, it is for students who became inactive while they were students and then graduated (and therefore are extremely unlikely to have any alumni engagement).