added Artifact api and passing unit tests
Merge branch 'david-api' of https://github.com/Kae7in/cs373-idb into david-api

Conflicts:
	hogwarts/marauder/views.py
Merge branch 'david-api' of https://github.com/Kae7in/cs373-idb into isabella_testapi

Conflicts:
	hogwarts/marauder/testapi.py