Merge pull request #144 from lmle/feat/client/ab_test

(test) ab_test: Add tests for services
Update data object in ab_tests queries to match agreed upon API
Add insert imgs and return data needed for client url construction
Merge pull request #145 from armandopmj/feat/imgsInsert

(feat) Add insert imgs and return data needed for client url construction
(feat) ab_test: Return image and reroute link to be used in emails