(For Yoav) Support returned actions

[nickhurlburt]

@yschatzberg this addresses #23 as well as #12926 in the main repository.

cc @safoo @aaronTufts @jburnim

[yschatzberg]

If both returnScore and returnAction are true, the url string generated would be:

https://api.siftscience.com/v203/events?return_score=true?return_action=true

Which is invalid. It should be:
https://api.siftscience.com/v203/events?return_score=true&return_action=true

[yschatzberg]

@nickhurlburt commented on an issue, otherwise LGTM

[nickhurlburt]

That's an important issue! Thanks for spotting that. I changed the code to handle multiple parameters correctly. Note that in our API service currently, if return_score=true is present, we actually ignore returnAction (that happens in L192 here). I think it's the right thing to pass the client's wishes through to the service so that the logic is only in the service, so the client can still pass in ?return_score=true&return_action=true, even if return_action will be ignored. I am not sure what additional documentation we should have to reflect that.

Let me know if you have more comments, otherwise I'll merge this in near the end of the day.

[yschatzberg]

While we're making changes to the Client library, perhaps if we modify the description of $returnScore to indicate that it is depreciated and $returnAction should be used instead. Other than that LGTM.

[nickhurlburt]

Comments have been added. I'll merge after the integration build runs.