In `hack/test-go.sh` treat arguments that start with a dash as go flags.

This fixes `hack/test-go.sh pkg/apiserver -test.run=<a_specific_test_name>`
which was broken by PR #1116.

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Also assume arguments starting with dashes are go flags in `hack/build-go.sh`

Tested:
  $ hack/build-go.sh cmd/kubelet -v
  github.com/GoogleCloudPlatform/kubernetes/pkg/...

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Merge pull request #1159 from filbranden/hack_test_goflags1

In hack/test-go.sh, treat arguments that start with a dash as go flags.