Put all test-related packages there (sample, testhelper, integration).
production risk: none
Change-Id: I06673aaa5c3fd6966410f1c1ad2b34e4f2d88f94
Reviewed-on: https://team-review.git.corp.google.com/c/golang/discovery/+/599080
CI-Result: Cloud Build <devtools-proctor-result-processor@system.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Jonathan Amsterdam