Adds an optional golang runner to the conformance test image

Adds a go app which runs the e2e tests with ginkgo.

 - Supports all the existing env vars of the bash script
 - Improved flow control to avoid and better report issues
regarding the process PID
 - Adds flags for modifying where to find the test binary and
ginkgo binary so that you can run it locally
 - Adds 3 flags for specifying extra args before the double-dash,
extra args after the double-dash, and the seperator to use between
values in those env vars. This allows setting arbitrary, complex
values for use on the command such as flags which include spaces
or other characters.

hack/lib/golang.sh

@@ -264,6 +264,7 @@ kube::golang::test_targets() {
     cmd/linkcheck
     vendor/github.com/onsi/ginkgo/ginkgo
     test/e2e/e2e.test
+    cluster/images/conformance/go-runner
   )
   echo "${targets[@]}"
 }