chore: release 2.21.0

Author: release-please[bot]

CHANGELOG.md

@@ -4,6 +4,18 @@
 
 [1]: https://pypi.org/project/google-cloud-bigquery/#history
 
+## [2.21.0](https://www.github.com/googleapis/python-bigquery/compare/v2.20.0...v2.21.0) (2021-06-22)
+
+
+### Features
+
+* enable unsetting policy tags on schema fields ([#703](https://www.github.com/googleapis/python-bigquery/issues/703)) ([18bb443](https://www.github.com/googleapis/python-bigquery/commit/18bb443c7acd0a75dcb57d9aebe38b2d734ff8c7))
+
+
+### Documentation
+
+* omit mention of Python 2.7 in `CONTRIBUTING.rst` ([#706](https://www.github.com/googleapis/python-bigquery/issues/706)) ([27d6839](https://www.github.com/googleapis/python-bigquery/commit/27d6839ee8a40909e4199cfa0da8b6b64705b2e9))
+
 ## [2.20.0](https://www.github.com/googleapis/python-bigquery/compare/v2.19.0...v2.20.0) (2021-06-07)
 
 

google/cloud/bigquery/version.py

@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "2.20.0"
+__version__ = "2.21.0"