Merge pull request #18 from penzance/html_update

Html update
Additional tests from feature/tracks_activation compatible with the older code
(These were new tests written of older code, as opposed to the tests written for new code in tracks_activation)
Merge branch 'feature/test_coverage' into feature/track_activation

Conflicts:
	ab_testing_tool_app/exceptions.py
	ab_testing_tool_app/tests/common.py
	ab_testing_tool_app/tests/test_controllers.py
	ab_testing_tool_app/tests/test_decorators.py
	ab_testing_tool_app/tests/test_selection_pages.py
	ab_testing_tool_app/tests/test_stage_pages.py
	ab_testing_tool_app/tests/test_track_pages.py