WIP - working on cloud storage import
Add import_data_from_uris and wait_for_job

The import_data_from_uris method imports data from Google Cloud
Storage.   The wait_for_job method takes a job resource or jobId
and waits until the job completes, polling with a user-specified interval
and timing out after a different user-specified interval.
Add wait_for_job test

Ensure that wait_for_job accepts a jobId.
Fix flake8 issues
Merge branch 'master' into cloudStorage
Test return type from BigQueryClient.wait_for_job is a dict
Log errors when .create_dataset fails
Merge branch 'master' into cloudStorage
Fix source_format constants used by import_data_from_uris
Fix bug: BigQuery load jobs now work

Got rid of the default values in import_data_from_uri.  If values are not
provided, they are not inserted into the load configuration.  Also fixed
the structure of the load configuration JSON.  Still need to write tests.
Merge remote-tracking branch 'original/master'
Update tests to be consistent with BigQuery results

Previous commits fixed the client after testing directly with BigQuery.
This commit fixes the tests to reflect the actual return values from
BigQuery, and adds tests for parameters to import_data_from_uris,
some of which are not permitted when source_format is not "CSV".
Fix import_data_from_uris documentation
Fix flake8 violations
Fix import_data_from_uris docstring and parameter order

Optional parameters are not injected into the job configuration,
default values are given by BigQuery.  The docstring now
correctly explains this.  Also shortened some constants.
Merge pull request #17 from aneilbaboo/master

Enable data import from Google Cloud Storage files