Update .travis.yml to use go 1.9.x

shawn1m · shawn1m · commit 05f1ac4ee783 · 2018-01-26T15:29:37.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,6 @@
 language: go
 go:
-  - 1.8.x
+  - 1.9.x
 addons:
   apt:
     packages:
