[infra] Update to Go 1.9.4

Bug: skia:
Change-Id: I55bb57a7f199d0f57531523f1fedfec2bf49502c
Reviewed-on: https://skia-review.googlesource.com/106802
Commit-Queue: Eric Boren <borenet@google.com>
Reviewed-by: Stephan Altmueller <stephana@google.com>
diff --git a/infra/bots/assets/go/VERSION b/infra/bots/assets/go/VERSION
index e440e5c8..bf0d87a 100644
--- a/infra/bots/assets/go/VERSION
+++ b/infra/bots/assets/go/VERSION
@@ -1 +1 @@
-3
\ No newline at end of file
+4
\ No newline at end of file
diff --git a/infra/bots/assets/go/create.py b/infra/bots/assets/go/create.py
index 424820f..577b852 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/go1.9.1.linux-amd64.tar.gz"
+GO_URL = "https://storage.googleapis.com/golang/go1.9.4.linux-amd64.tar.gz"
 
 def create_asset(target_dir):
   """Create the asset."""
diff --git a/infra/bots/tasks.json b/infra/bots/tasks.json
index d31232b8..9d48b34 100644
--- a/infra/bots/tasks.json
+++ b/infra/bots/tasks.json
@@ -6078,7 +6078,7 @@
         {
           "name": "skia/bots/go",
           "path": "go",
-          "version": "version:3"
+          "version": "version:4"
         }
       ],
       "dependencies": [
@@ -6113,7 +6113,7 @@
         {
           "name": "skia/bots/go",
           "path": "go",
-          "version": "version:3"
+          "version": "version:4"
         }
       ],
       "dimensions": [
@@ -6168,7 +6168,7 @@
         {
           "name": "skia/bots/go",
           "path": "go",
-          "version": "version:3"
+          "version": "version:4"
         }
       ],
       "dependencies": [
@@ -6201,7 +6201,7 @@
         {
           "name": "skia/bots/go",
           "path": "go",
-          "version": "version:3"
+          "version": "version:4"
         }
       ],
       "dependencies": [
@@ -6288,7 +6288,7 @@
         {
           "name": "skia/bots/go",
           "path": "go",
-          "version": "version:3"
+          "version": "version:4"
         }
       ],
       "dimensions": [
@@ -6420,7 +6420,7 @@
         {
           "name": "skia/bots/go",
           "path": "go",
-          "version": "version:3"
+          "version": "version:4"
         }
       ],
       "dimensions": [