Release Spanner 0.21.0

Initial implementation of the Google Cloud Spanner API Ruby client.

Release Google Cloud 0.32.0

* Add Spanner (google-cloud-spanner)

Release google-cloud-storage 1.1.0

* Add Bucket#labels.
* Update gem spec homepage links.
* Remove memoization of Policy.
* Deprecate force parameter in Bucket#policy. (Will be removed in a
  future version.)
* Deprecate Policy#deep_dup. (Will be removed in a future version.)

Release google-cloud-resource_manager 0.25.0

* Fix apiary client argument case.
* Update gem spec homepage links.
* Remove memoization of Policy.
* Remove force parameter from Project#policy.
* Remove Policy#deep_dup.

Release google-cloud-pubsub 0.25.0

* Add Snapshot and Subscription#seek.
* Add Subscription#retain_acked and Subscription#retention.
* Update gem spec homepage links.
* Remove memoization of Policy.
* Remove force parameter from Subscription#policy and Topic#policy.
* Remove Policy#deep_dup.
* Configure gRPC max_send_message_length and max_receive_message_length
to accommodate max message size > 4 MB.

Release google-cloud 0.31.0

* Pub/Sub 0.25.0 release
* Resource Manager 0.25.0 release
* Storage 1.1.0 release

Release stackdriver 0.6.0.

* Debugger 0.25.0 release.
* Error Reporting 0.25.0 release.
* Logging 1.1.0 release.
* Trace 0.25.0 release.
* Remove `google-cloud-monitoring` from this umbrella gem.

Release google-cloud-trace 0.25.0.

* Introduce new `Google::Cloud::Trace.configure` instrumentation
configuration interface.

Release google-cloud-logging 1.1.0. Introduce new configuration inter…

…face. Logger sends more trace context info.

Release google-cloud-error_reporting 0.25.0.

* New Error Reporting instrumentation client.
* Introduce simple `Google::Cloud::ErrorReporting.report` interface to
easily report Ruby exception.
* New `Google::Cloud::ErrorReporting.configure` instrumentation
configuration interface.
* `Google::Cloud::ErrorReporting::Middleware` can now be used without
required parameters.