Changed table to reflect new tutoring hours
Added static mockup for classes popover
Improved static mockup: removed old key, added a new one, made class list in popover a nice table, some other things I forget
Made static example less static
Added uids for all users in table
Slight change to key table layout
Made tutoring page responsive
Support backend for new tutoring hover overs.

* Add Subject class
   * Register it in admin

* Add necessary methods to jsonify the subject
  relationship into useable format
Views: Pull from backend for tutoring.

Now, we have classes set in the DB.

This queries the DB for all relevant staff subject
lists and pushes it onto the tutoring template.
Flake8 fixes.
DB: Add migration to add subject table.