Release Pub/Sub 0.31.1

* Fix bug in AsyncUnaryPusher,
  * The modify_ack_deadline requests were malformed.

Release google-cloud-os_login 0.2.0 with support for v1 of the API

Release BigQuery DataTransfer v0.2.0

Release google-cloud-vision v0.30.0

* Add async_batch_annotate_files method to Google::Cloud::Vision::Project

Release google-cloud-dlp 0.5.0

* Documentation update
* Credentials env_vars change

Release google-cloud-text_to_speech 0.1.0

Release google-cloud-kms 0.2.0

Release google-cloud-trace 0.33.1

* Fix issue when disabling Stackdriver components with Rails.env.production.
* Add /healthz to the ignored requests. (diegodurs)
* Add documentation for enabling gRPC logging.

Release google-cloud-logging 1.5.1

* Fix bug in List classes by propagating arguments needed for pagination calls.
* Fix issue when disabling Stackdriver components with Rails.env.production.
* Reduce string memory usage.
* Add documentation for enabling gRPC logging.

Release google-cloud-kms v0.1.0

* Initial release.