Default ingress to route on openshift

[Karen-Schoener]

On openshift, if skupper init is called with ingress='' or with no ingress param specified, default ingress to route.

Fixes #1424

[Karen-Schoener]

Marking as draft. Plan to test more before asking for review comments.

[Karen-Schoener]

Tested with minikube: ./skupper init

  $ ./skupper init
  $ kubectl get configmap skupper-site -o yaml | grep ingress
  ingress: loadbalancer

Tested with minikube: ./skupper init --ingress ''

  $ ./skupper init --ingress '' 
  $   kubectl get configmap skupper-site -o yaml | grep ingress
  ingress: loadbalancer

Tested with openshift-local: ./skupper init

  $ ./skupper init
  $ oc get configmap skupper-site -o yaml | grep ingress
  ingress: route

Tested with openshift-local: ./skupper init --ingress ''

  $ ./skupper init --ingress '' 
  $ oc get configmap skupper-site -o yaml | grep ingress
  ingress: route

[Karen-Schoener]

Removed draft label.

[grs]

This looks good to me, thank you!