kubectl get pods and logs commands in README don't work because of label changes

[kevinearls]

The README includes the following commands

kubectl get pods -l jaeger=simplest
kubectl logs -l jaeger=simplest

Currently neither of these work as the jaeger label doesn't exist. As a workaround we can do:

kubectl get pods -l app.kubernetes.io/instance=simplest
kubectl logs -l app.kubernetes.io/instance=simplest

NOTE: On Openshift the kubectl logs command also requires that the container name be specified.

[jpkrohling]

The question is whether we want to add a label "jaeger" again, to make it easier to query the objects related to simplest. The same can be done by querying based on the label app.kubernetes.io/instance, but that's a lot more work than just typing jaeger.

[jpkrohling]

Done as part of #225, we won't be re-adding the jaeger entry for now.