Effectively express in the database which professors are teaching which classes, and when

@mfekadu
## Objective
Need to be able to link the professors and courses. Currently, in the database there is no expression of a particular professor teaching a particular course.

## Key Result
Pick one of the strategies below to link courses and professors

## Details
Ways to go about this could be:
- adding the professor_id to the Courses table
- creating a "Teaches" table to have the course id and professor id
- to create a full "Schedule" table to include office hours, classes being taught, and all agenda data for a professor