chore: release 2.6.0 (#236)
chore: release 2.6.0 (#236)

:robot: I have created a release \*beep\* \*boop\*
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## [2.6.0](https://www.github.com/googleapis/python-monitoring/compare/v2.5.2...v2.6.0) (2021-11-01)


### Features

* add context manager support in client ([#230](https://www.github.com/googleapis/python-monitoring/issues/230)) ([954dd18](https://www.github.com/googleapis/python-monitoring/commit/954dd18966520dbc623470ef528166d83d3e19ba))
* add CreateServiceTimeSeries RPC ([#235](https://www.github.com/googleapis/python-monitoring/issues/235)) ([2970b22](https://www.github.com/googleapis/python-monitoring/commit/2970b22ca5b4959ee1d3e1e883cdb00951e3917f))


### Bug Fixes

* **deps:** drop packaging dependency ([22d4eab](https://www.github.com/googleapis/python-monitoring/commit/22d4eabbafbdc16b0f4faf66f966442691de7666))
* **deps:** require google-api-core >= 1.28.0 ([22d4eab](https://www.github.com/googleapis/python-monitoring/commit/22d4eabbafbdc16b0f4faf66f966442691de7666))
* Reintroduce deprecated field/enum `ServiceTier` for backward compatibility ([#240](https://www.github.com/googleapis/python-monitoring/issues/240)) ([eeb0534](https://www.github.com/googleapis/python-monitoring/commit/eeb05347eaf6e7a0794e679d83fe70a0db6a02a3))


### Documentation

* list oneofs in docstring ([22d4eab](https://www.github.com/googleapis/python-monitoring/commit/22d4eabbafbdc16b0f4faf66f966442691de7666))
* Use absolute link targets in comments ([eeb0534](https://www.github.com/googleapis/python-monitoring/commit/eeb05347eaf6e7a0794e679d83fe70a0db6a02a3))
---


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