[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>
3 files changed