updates to utilize multiple api hosts

- details here https://github.com/airbnb/rendr/pull/45
fixing `undefined` bug + updating production conf to mirror development conf file
main -> default
renaming apis -> apiHosts to match internal copy supporting this feature

- also feels more semantically correct
Updating multiple API host example to match new Rendr commits
Merge pull request #23 from airbnb/multiple-api-hosts

Multiple api hosts