Merge branch 'master' into feature/mutli_exp_part2

Conflicts:
	ab_tool/urls.py
Merge branch 'feature/mutli_exp_part2' into feature/multi_exp_part2.5
Merge branch 'feature/multi_exp_part2.5' into develop
Merge branch 'develop' of github.com:penzance/ab-testing-tool into develop