Staff page staff list and add staff

[andrew-kwon1]

Admin can see all staff in a course Admin can add a staff member to a course

dokku deployment: https://organic-andrewkwon.dokku-11.cs.ucsb.edu

reopened/redid pull request #66

Closes #26 Closes #27

[andrew-kwon1]

I'm not sure what still needs to be fixed.