BigQuery

## wip.

#### Docs: https://stephenplusplus.github.io/gcloud-node/#/docs/master/bigquery

Carrying on from #262. Just opening this so anyone interested can follow along.

This whole thing is hard to follow. I'd say we could consider building the entire thing from a template before writing, but I'm not sure how streams chunk data and if the whole string should be sent in one piece to the stream.