chore: release pubsub 1.15.0 (#4593)

🤖 I have created a release \*beep\* \*boop\*
---
## [1.15.0](https://www.github.com/googleapis/google-cloud-go/compare/pubsub/v1.14.0...pubsub/v1.15.0) (2021-08-13)


### Features

* **pubsub:** Add topic retention options ([5996846](https://www.github.com/googleapis/google-cloud-go/commit/59968462a3870c6289166fa1161f9b6d9c10e093))


### Bug Fixes

* **pubsub:** always make config check to prevent race ([#4606](https://www.github.com/googleapis/google-cloud-go/issues/4606)) ([8cfcf53](https://www.github.com/googleapis/google-cloud-go/commit/8cfcf53d03b9b442e7f0bc1c1b20c791e31c07b0)), refs [#3626](https://www.github.com/googleapis/google-cloud-go/issues/3626)
* **pubsub:** mitigate race in checking ordering config ([#4602](https://www.github.com/googleapis/google-cloud-go/issues/4602)) ([112eea2](https://www.github.com/googleapis/google-cloud-go/commit/112eea20b46bbc34e5f8f65b9812fb3e60107409)), refs [#3626](https://www.github.com/googleapis/google-cloud-go/issues/3626)
* **pubsub:** replace IAMPolicy in API config ([5996846](https://www.github.com/googleapis/google-cloud-go/commit/59968462a3870c6289166fa1161f9b6d9c10e093))

This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please).

pubsub/CHANGES.md

@@ -1,5 +1,19 @@
 # Changes
 
+## [1.15.0](https://www.github.com/googleapis/google-cloud-go/compare/pubsub/v1.14.0...pubsub/v1.15.0) (2021-08-13)
+
+
+### Features
+
+* **pubsub:** Add topic retention options ([5996846](https://www.github.com/googleapis/google-cloud-go/commit/59968462a3870c6289166fa1161f9b6d9c10e093))
+
+
+### Bug Fixes
+
+* **pubsub:** always make config check to prevent race ([#4606](https://www.github.com/googleapis/google-cloud-go/issues/4606)) ([8cfcf53](https://www.github.com/googleapis/google-cloud-go/commit/8cfcf53d03b9b442e7f0bc1c1b20c791e31c07b0)), refs [#3626](https://www.github.com/googleapis/google-cloud-go/issues/3626)
+* **pubsub:** mitigate race in checking ordering config ([#4602](https://www.github.com/googleapis/google-cloud-go/issues/4602)) ([112eea2](https://www.github.com/googleapis/google-cloud-go/commit/112eea20b46bbc34e5f8f65b9812fb3e60107409)), refs [#3626](https://www.github.com/googleapis/google-cloud-go/issues/3626)
+* **pubsub:** replace IAMPolicy in API config ([5996846](https://www.github.com/googleapis/google-cloud-go/commit/59968462a3870c6289166fa1161f9b6d9c10e093))
+
 ## [1.14.0](https://www.github.com/googleapis/google-cloud-go/compare/pubsub/v1.13.0...pubsub/v1.14.0) (2021-08-09)