Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>..
k8s.io/code-generator: hide gen test output from go tools
The underscore in front of _test makes the go tools (including godep) to
ignore those packages by default. We do not want to create dependencies
to client-go and friends through the _test output.
fe4b35a22f