infra recipe: Add -t flag to "go test"

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4896

Change-Id: Iff66f67a28b65797446d0ba26064f00dc948bb47
Reviewed-on: https://skia-review.googlesource.com/4896
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
6 files changed