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: 
Right, cause the function works. We don't want tests that depend completely on the behavior of our test stubs. If `delete` is changed to no longer make a call to makeReq_, instead doing something unknown with the callback, this can at least handle a provided error properly. There's a test below to see that the passed callback executes.