Add a prefix option to e2e for use with resources

This is helpful when cleaning manually up after a failed test in
shared a gce environment.

Signed-off-by: Sami Wagiaalla <swagiaal@redhat.com>

test/e2e/e2e_test.go

@@ -101,6 +101,7 @@ func init() {
 	flag.StringVar(&testContext.Provider, "provider", "", "The name of the Kubernetes provider (gce, gke, local, vagrant, etc.)")
 	flag.StringVar(&testContext.KubectlPath, "kubectl-path", "kubectl", "The kubectl binary to use. For development, you might use 'cluster/kubectl.sh' here.")
 	flag.StringVar(&testContext.OutputDir, "e2e-output-dir", "/tmp", "Output directory for interesting/useful test data, like performance data, benchmarks, and other metrics.")
+	flag.StringVar(&testContext.prefix, "prefix", "e2e", "A prefix to be added to cloud resources created during testing.")
 
 	// TODO: Flags per provider?  Rename gce-project/gce-zone?
 	flag.StringVar(&cloudConfig.MasterName, "kube-master", "", "Name of the kubernetes master. Only required if provider is gce or gke")