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 'develop' into feature/test_refactor

Conflicts:
	ab_tool/tests/common.py
	ab_tool/tests/test_intervention_point_pages.py
	ab_tool/tests/test_main_pages.py
	ab_tool/tests/test_track_pages.py
Merge branch 'develop' into feature/test_refactor

Conflicts:
	ab_tool/exceptions.py
	ab_tool/models.py
	ab_tool/views/intervention_point_pages.py
	ab_tool/views/track_pages.py
comment update
Merge branch 'develop' into feature/test_refactor
implements changes for multi-experiment support to models and controlers