Call go fmt, go lint, go test and go vet
(via go test) during presubmit and git hooks.

Will only warn when the go commands are not available
as go is not part of depot_tools.

BUG=chromium:976903
TEST=Tried with and without go/gofmt/golint in the path.
TEST=Tried on go and non go files.
TEST=Tried on go files with and without errors.

Change-Id: I8a6aa4227f0d8649f7c390ab59f187f14955293c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/1669745
Reviewed-by: George Burgess <gbiv@chromium.org>
Commit-Queue: Tobias Bosch <tbosch@google.com>
Tested-by: Tobias Bosch <tbosch@google.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
3 files changed