Add E2E tests for HealthCheck

Adds e2e tests for:

- upstream-max-fails
- upstream-fail-timeout

test/e2e/framework/exec.go

@@ -50,6 +50,7 @@ func (f *Framework) ExecCommand(pod *v1.Pod, command string) (string, error) {
 
 // NewIngressController deploys a new NGINX Ingress controller in a namespace
 func (f *Framework) NewIngressController(namespace string) error {
+	// Creates an nginx deployment
 	cmd := exec.Command("./wait-for-nginx.sh", namespace)
 	out, err := cmd.CombinedOutput()
 	if err != nil {