Associate Classes with Notes

## Description
This change is a necessary change for live updating snippets since we need multiple people in a single class. So like the title states, I've created a class with a teacher in a room during a semester which will be associated with the notes of two users. 

**This requires a change to the database** but I've included a shell script to create and load the database easily. The command executed in the schema folder `./db create` will just create the database while `./db load` will create and then load all the data.

Also, **the test user email has changed** to `test1@test.com` and another has been made at ``test2@test.com`.