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.

Sorry, I must have missed this comment from yesterday. I've added in a little more: https://github.com/stephenplusplus/gcloud-node/commit/cbcf4ce92842b3f3790dffd9fc63d87f8d1ef212