Resolves #37 #44 "JUnit Test Output" and "Add a test coverage metric for python code"

Closes #37 (closed), #44 (closed)

Notes

Changes from APITestCase's from the djangorestframework back to TestCases used by the regular Django framework due to having better integration. Additionally adds a configuration file and updates to the requirements file to allow coverage reports to be generated. Also adds report writing (both machine parsable text and human-readable HTML) to the pipeline, as well as correct regex into the settings to allow for coverage parsing for more code metrics.

Additionally, adds an extra job that fails the pipeline if the current branch's coverage is lower than master's.