Add api/report_session_start
Fix travis tests
Support report_session_end
Properly fail for ending nonexisting sessions
Fail for ending session multiple times
Slight refactoring
Support report_test_start
Test API support
intermidiate stuff, will probably change
Merge remote-tracking branch 'upstream/master'

Conflicts:
	flask_app/app.py
	flask_app/models.py
logical_id to session and test plus add_product