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: 
This `describe()` just slaps himself right in the middle of two outer `it()`. Please reorder the tests or group them in describes for organization.