chore: release 3.1.0 (#116)

🤖 I have created a release \*beep\* \*boop\*
---
## [3.1.0](https://www.github.com/googleapis/python-bigquery-datatransfer/compare/v3.0.1...v3.1.0) (2021-03-22)


### Features

* add `client_cert_source_for_mtls` parameter to grpc transport ([#114](https://www.github.com/googleapis/python-bigquery-datatransfer/issues/114)) ([9c7ed28](https://www.github.com/googleapis/python-bigquery-datatransfer/commit/9c7ed285203cd44917911e78c2c313d3ad50afda))
---


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

Author: release-please[bot]

CHANGELOG.md

@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-cloud-bigquery-datatransfer/#history
 
+## [3.1.0](https://www.github.com/googleapis/python-bigquery-datatransfer/compare/v3.0.1...v3.1.0) (2021-03-22)
+
+
+### Features
+
+* add `client_cert_source_for_mtls` parameter to grpc transport ([#114](https://www.github.com/googleapis/python-bigquery-datatransfer/issues/114)) ([9c7ed28](https://www.github.com/googleapis/python-bigquery-datatransfer/commit/9c7ed285203cd44917911e78c2c313d3ad50afda))
+
 ### [3.0.1](https://www.github.com/googleapis/python-bigquery-datatransfer/compare/v3.0.0...v3.0.1) (2021-03-03)
 
 

setup.py

@@ -22,7 +22,7 @@
 
 name = "google-cloud-bigquery-datatransfer"
 description = "BigQuery Data Transfer API client library"
-version = "3.0.1"
+version = "3.1.0"
 # Should be one of:
 # 'Development Status :: 3 - Alpha'
 # 'Development Status :: 4 - Beta'