Start building with Go 1.9 as well.

Diwaker Gupta · Diwaker Gupta · commit 6596ac9e2491 · 2017-08-28T09:14:21.000-07:00
diff --git a/.travis.yml b/.travis.yml
@@ -4,6 +4,7 @@ go:
   - 1.6.4
   - 1.7.6
   - 1.8.3
+  - 1.9
 
 install:
   - go get -u golang.org/x/oauth2
