Update to go 1.9

Bug: skia:
Change-Id: Idda5c247895031982d19534197bc1b6ab5f6e4da
Reviewed-on: https://skia-review.googlesource.com/58000
Reviewed-by: Stephan Altmueller <stephana@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
diff --git a/infra/bots/assets/go/create.py b/infra/bots/assets/go/create.py
index af72be8..424820f 100755
--- a/infra/bots/assets/go/create.py
+++ b/infra/bots/assets/go/create.py
@@ -12,7 +12,7 @@
 import argparse
 import subprocess
 
-GO_URL = "https://storage.googleapis.com/golang/go1.8.2.linux-amd64.tar.gz"
+GO_URL = "https://storage.googleapis.com/golang/go1.9.1.linux-amd64.tar.gz"
 
 def create_asset(target_dir):
   """Create the asset."""