chore: release 1.4.0 (#42)

* updated CHANGELOG.md [ci skip]

* updated setup.py [ci skip]

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

Author: release-please[bot]

CHANGELOG.md

@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-cloud-pubsub/#history
 
+## [1.4.0](https://www.github.com/googleapis/python-pubsub/compare/v1.3.1...v1.4.0) (2020-03-06)
+
+
+### Features
+
+* **pubsub:** implement max_duration_per_lease_extension option ([#38](https://www.github.com/googleapis/python-pubsub/issues/38)) ([d911a2d](https://www.github.com/googleapis/python-pubsub/commit/d911a2dc8edf3c348ad3f128368b30e32dbc449e))
+
 ### [1.3.1](https://www.github.com/googleapis/python-pubsub/compare/v1.3.0...v1.3.1) (2020-02-28)
 
 

setup.py

@@ -22,7 +22,7 @@
 
 name = "google-cloud-pubsub"
 description = "Google Cloud Pub/Sub API client library"
-version = "1.3.1"
+version = "1.4.0"
 # Should be one of:
 # 'Development Status :: 3 - Alpha'
 # 'Development Status :: 4 - Beta'