Monkeypatch to pass array params without an index

https://github.com/typhoeus/typhoeus/issues/320

We were seeing array params tranformed into the following:
/event?groups[0]=open-forum&groups[1]=armory-films

but we need the client to send array params to various API
services in the following (valid) format:
/event?groups[]=open-forum&groups[]=armory-films