Release google-cloud-pubsub 1.10.0 (googleapis#7082)

#### Features

* Add Subscription#detach and #detached?

Release google-cloud-trace 0.40.0 (googleapis#7081)

Updated to use the microgenerator-produced gapics.

Release google-cloud-spanner-admin-instance-v1 0.1.1 (googleapis#7077)

* Make the spanner env prefixes consistent

Release google-cloud-spanner-admin-database-v1 0.1.1 (googleapis#7070)

* Make the spanner env prefixes consistent
* Allow retries of UpdateBackup

Release google-cloud-spanner 2.0.0 (googleapis#7080)

Updated to use the microgenerator-produced gapics.

Release google-cloud-pubsub 1.10.0 (googleapis#7082)

#### Features

* Add Subscription#detach and #detached?

Release google-cloud-bigtable 1.3.0 (googleapis#7053)

#### Features

* Add Managed Backups
  * Add Cluster#create_backup, Cluster#backup and Cluster#backups
  * Add Backup, Backup::Job and Backup::List
  * Add Table::RestoreJob
  * Add ClusterState#ready_optimizing?

Release google-cloud-pubsub 1.9.0 (googleapis#6997)

#### Features

* Add support for server-side flow control

Release google-cloud-logging 2.0.0 (googleapis#7064)

* Update to use the microgenerator-generated low-level client

Release google-cloud-error_reporting 0.40.0 (googleapis#7063)

* Update to use the microgenerator-generated low-level client