chore: release 1.13.1 (#482)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ed2b168..c465e6c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-auth/#history
 
+### [1.13.1](https://www.github.com/googleapis/google-auth-library-python/compare/v1.13.0...v1.13.1) (2020-04-01)
+
+
+### Bug Fixes
+
+* invalid expiry type ([#481](https://www.github.com/googleapis/google-auth-library-python/issues/481)) ([7ae9a28](https://www.github.com/googleapis/google-auth-library-python/commit/7ae9a284dae16d274bfd4d876414f08efd6c3bff))
+
 ## [1.13.0](https://www.github.com/googleapis/google-auth-library-python/compare/v1.12.0...v1.13.0) (2020-04-01)
 
 
diff --git a/setup.py b/setup.py
index 0930fd8..cb6ed5a 100644
--- a/setup.py
+++ b/setup.py
@@ -30,7 +30,7 @@
 with io.open("README.rst", "r") as fh:
     long_description = fh.read()
 
-version = "1.13.0"
+version = "1.13.1"
 
 setup(
     name="google-auth",