Test audit

[dpgraham4401]

Description

This PR makes improvements to our trak and sites django app test suites.
For each unit test, we evaluated the following questions

1. do we need it?
2. Is it readable
3. can we clearly discern the three stages, AAA

We also made some minor modification to things such as class names to be internally consistent, refactored a couple things to make use of Django and DRF's built in functionality to remove boilerplate, and update the server dependencies (see #423, and #424)

Issue ticket number and link

relevant to #128

Checklist

• I have added tests that prove my fix is effective or that my feature works
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Other Stuff