chore: release 1.31.0

Author: release-please[bot]

CHANGELOG.md

@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-api-core/#history
 
+## [1.31.0](https://www.github.com/googleapis/python-api-core/compare/v1.30.0...v1.31.0) (2021-06-16)
+
+
+### Features
+
+* add ServiceUnavailable exception to polling retries ([#184](https://www.github.com/googleapis/python-api-core/issues/184)) ([11032cf](https://www.github.com/googleapis/python-api-core/commit/11032cf08ecc16dd252a6cda8b33b0b28ec4f4ba))
+
 ## [1.30.0](https://www.github.com/googleapis/python-api-core/compare/v1.29.0...v1.30.0) (2021-06-08)
 
 

google/api_core/version.py

@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "1.30.0"
+__version__ = "1.31.0"