Rethinkdb integration.

[fabianmarz]

@yasserf, did you start migrating the rethinkDB integration for this module? The existing module https://www.npmjs.com/package/deepstream.io-provider-search-rethinkdb is outdated and I assume also kind of deprecated as the new one is using a newer structure and RPC? Also the database client is currently hardcoded to MongoDB for the new module. Just wondering if there are unpushed changes somewhere before starting to get my hands on :)

Thanks for the good work!

[yasserf]

Doesn't look like I did! You can migrate the code from the rethinkdb-provider to match the typescript structure