refactors tests in preperation for the multi-experiment refactor
adds several fields and methods to models to spoof new behavior that will be introduced in the multi-experiemnt code
Merge branch 'feature/test_refactor' into feature/experiment

Conflicts:
	ab_tool/models.py
	ab_tool/tests/test_intervention_point_pages.py
	ab_tool/views/intervention_point_pages.py
	ab_tool/views/track_pages.py