BigQuery

#### Docs: https://stephenplusplus.github.io/gcloud-node/#/docs/master/bigquery

##### Todo List (current):

- [x] Unit tests
- [x] Regression tests
- [ ] Update use cases from the doc examples to less kitten-based use cases :smirk_cat: 
Can we pull this require('extend') out into its own assignment. It will help me sleep better at night.