modules: bump 1.9 to 1.11

Change-Id: Icec7ad2cd37cf342f0f0e143547cc557c7d25b44
Reviewed-on: https://code-review.googlesource.com/c/google-api-go-client/+/46274
Reviewed-by: Tyler Bui-Palsulich <tbp@google.com>
Reviewed-by: kokoro <noreply+kokoro@google.com>
diff --git a/go.mod b/go.mod
index 63abbca..c8db20b 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module google.golang.org/api
 
-go 1.9
+go 1.11
 
 require (
 	cloud.google.com/go v0.38.0 // indirect