chore: release 3.12.1 (googleapis#658)

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chore: release 3.12.0 (googleapis#614)

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chore: release 3.11.1 (googleapis#607)

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Co-authored-by: Vikash Singh <3116482+vi3k6i5@users.noreply.github.com>

chore: release 3.11.0 (googleapis#599)

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chore: release 3.10.0 (googleapis#567)

🤖 I have created a release \*beep\* \*boop\*
---
## [3.10.0](https://www.github.com/googleapis/python-spanner/compare/v3.9.0...v3.10.0) (2021-09-17)


### Features

* set a separate user agent for the DB API ([googleapis#566](https://www.github.com/googleapis/python-spanner/issues/566)) ([b5f977e](https://www.github.com/googleapis/python-spanner/commit/b5f977ebf61527914af3c8356aeeae9418114215))


### Bug Fixes

* **db_api:** move connection validation into a separate method ([googleapis#543](https://www.github.com/googleapis/python-spanner/issues/543)) ([237ae41](https://www.github.com/googleapis/python-spanner/commit/237ae41d0c0db61f157755cf04f84ef2d146972c))
* handle google.api_core.exceptions.OutOfRange exception and throw InegrityError as expected by dbapi standards ([googleapis#571](https://www.github.com/googleapis/python-spanner/issues/571)) ([dffcf13](https://www.github.com/googleapis/python-spanner/commit/dffcf13d10a0cfb6b61231ae907367563f8eed87))
---


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

chore: release 3.9.0 (googleapis#540)

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chore: release 3.8.0 (googleapis#480)

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Co-authored-by: larkee <31196561+larkee@users.noreply.github.com>

chore: release 3.7.0 (googleapis#398)

🤖 I have created a release \*beep\* \*boop\*
---
## [3.7.0](https://www.github.com/googleapis/python-spanner/compare/v3.6.0...v3.7.0) (2021-07-29)


### Features

* add always_use_jwt_access ([googleapis#381](https://www.github.com/googleapis/python-spanner/issues/381)) ([0f1a5de](https://www.github.com/googleapis/python-spanner/commit/0f1a5ded572685a96d29a60c959cb00a48f7a87f))
* add configurable leader placement support ([googleapis#399](https://www.github.com/googleapis/python-spanner/issues/399)) ([7f1b120](https://www.github.com/googleapis/python-spanner/commit/7f1b1209e62062014545cf959d41f04184552eec))
* add sample for low cost instances ([googleapis#392](https://www.github.com/googleapis/python-spanner/issues/392)) ([3f4f93f](https://www.github.com/googleapis/python-spanner/commit/3f4f93f75f5585a82047bf8d83a24622ad776ecb))


### Bug Fixes

* avoid bad version of `opentelemetry-instrumentation` ([googleapis#429](https://www.github.com/googleapis/python-spanner/issues/429)) ([1620c12](https://www.github.com/googleapis/python-spanner/commit/1620c12a56e0d007cf010690bab303db06d0c914))
* **deps:** pin 'google-{api,cloud}-core' to allow 2.x versions ([googleapis#415](https://www.github.com/googleapis/python-spanner/issues/415)) ([b0455d0](https://www.github.com/googleapis/python-spanner/commit/b0455d0ab657cd053a7527e99bdbfadc4de23b30))
* disable always_use_jwt_access ([c37bf21](https://www.github.com/googleapis/python-spanner/commit/c37bf21afdf417757eff67fe8500aa65f49fd5ad))
* disable always_use_jwt_access ([googleapis#395](https://www.github.com/googleapis/python-spanner/issues/395)) ([c37bf21](https://www.github.com/googleapis/python-spanner/commit/c37bf21afdf417757eff67fe8500aa65f49fd5ad))
* enable self signed jwt for grpc ([googleapis#427](https://www.github.com/googleapis/python-spanner/issues/427)) ([2487800](https://www.github.com/googleapis/python-spanner/commit/2487800e31842a44dcc37937c325e130c8c926b0))
* support merging for NUMERIC values ([googleapis#434](https://www.github.com/googleapis/python-spanner/issues/434)) ([06b4215](https://www.github.com/googleapis/python-spanner/commit/06b4215f76ae806eba1d0d07115c8c90b8c7482d)), closes [googleapis#433](https://www.github.com/googleapis/python-spanner/issues/433)


### Documentation

* fix docstring for session.py ([googleapis#387](https://www.github.com/googleapis/python-spanner/issues/387)) ([3132587](https://www.github.com/googleapis/python-spanner/commit/3132587453f7bd0be72ebc393626b5c8b1bab982))
---


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

chore: release 3.6.0 (googleapis#370)

* chore: release 3.6.0

* fix: add missing PR to CHANGELOG

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chore: release 3.5.0 (googleapis#349)

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