CONTRIBUTING: don't assume GOPATH is set
`go get -d github.com/GoogleCloudPlatform/golang-samples`
1. Change into the checked out source:
- `cd $GOPATH/src/github.com/GoogleCloudPlatform/golang-samples`
+ `cd $(go env GOPATH)/src/github.com/GoogleCloudPlatform/golang-samples`
1. Fork the repo.
1. Set your fork as a remote:
