Update dependency google-auth to v1.21.0 [(#4588)](#4588)

renovate-bot · busunkim96 · commit 170b5a338556 · 2020-09-29T10:46:26.000-06:00
diff --git a/language/snippets/api/requirements.txt b/language/snippets/api/requirements.txt
@@ -1,3 +1,3 @@
 google-api-python-client==1.10.1
-google-auth==1.20.1
+google-auth==1.21.0
 google-auth-httplib2==0.0.4
