chore: release 1.19.1 (googleapis#144)

🤖 I have created a release \*beep\* \*boop\* 
---
### [1.19.1](https://www.github.com/googleapis/python-spanner/compare/v1.19.0...v1.19.1) (2020-10-13)


### Bug Fixes

* handle Unmergable errors when merging struct responses ([googleapis#152](https://www.github.com/googleapis/python-spanner/issues/152)) ([d132409](https://www.github.com/googleapis/python-spanner/commit/d132409dd4300cb2dca7c4bc7dbdd4d429d2fa7c))


### Documentation

* update samples dep to 'google-cloud-spanner==1.19.0' ([googleapis#137](https://www.github.com/googleapis/python-spanner/issues/137)) ([0fba41a](https://www.github.com/googleapis/python-spanner/commit/0fba41a5c19b02b0424705618dd1e2e5ca12238f))
* update samples from python-docs-samples ([googleapis#146](https://www.github.com/googleapis/python-spanner/issues/146)) ([7549383](https://www.github.com/googleapis/python-spanner/commit/754938386c96814a3546d30d38d874734d1c201c))
---


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

chore: release 1.19.0 (googleapis#141)

* chore: updated CHANGELOG.md [ci skip]

* chore: updated setup.cfg [ci skip]

* chore: updated setup.py

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

chore: release 1.18.0 (googleapis#119)

* chore: updated CHANGELOG.md [ci skip]

* chore: updated setup.cfg [ci skip]

* chore: updated setup.py

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

chore: release 1.17.1 (googleapis#100)

* updated CHANGELOG.md [ci skip]

* updated setup.cfg [ci skip]

* updated setup.py

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

chore: release 1.17.0 (googleapis#88)

* updated CHANGELOG.md [ci skip]

* updated setup.cfg [ci skip]

* updated setup.py

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

chore: release 1.16.0 (googleapis#76)

* updated CHANGELOG.md [ci skip]

* updated setup.cfg [ci skip]

* updated setup.py [ci skip]

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
Co-authored-by: larkee <31196561+larkee@users.noreply.github.com>

chore: release 1.15.1 (googleapis#52)

* updated CHANGELOG.md [ci skip]

* updated setup.cfg [ci skip]

* updated setup.py [ci skip]

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

chore: release 1.15.0 (googleapis#40)

* updated CHANGELOG.md [ci skip]

* updated setup.py [ci skip]

* Update CHANGELOG.md

Tidy commit summaries

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
Co-authored-by: larkee <31196561+larkee@users.noreply.github.com>

chore: release 1.14.0 (googleapis#2)

* updated CHANGELOG.md [ci skip]

* updated setup.py [ci skip]

chore(spanner): release 1.13.0 (#9731)

* chore(spanner): release 1.13.0

* address PR comments