kubectl helpers

## Logs

```
kubectl logs my-pod                                 # dump pod logs (stdout)
kubectl logs -l name=myLabel                        # dump pod logs, with label name=myLabel (stdout)
kubectl logs my-pod --previous                      # dump pod logs (stdout) for a previous instantiation of a container
kubectl logs my-pod -c my-container                 # dump pod container logs (stdout, multi-container case)
kubectl logs -l name=myLabel -c my-container        # dump pod logs, with label name=myLabel (stdout)
kubectl logs my-pod -c my-container --previous      # dump pod container logs (stdout, multi-container case) for a previous instantiation of a container
kubectl logs -f my-pod                              # stream pod logs (stdout)
kubectl logs -f my-pod -c my-container              # stream pod container logs (stdout, multi-container case)
kubectl logs -f -l name=myLabel --all-containers    # stream all pods logs with label name=myLabel (stdout)

kubectl logs deploy/my-deployment                         # dump Pod logs for a Deployment (single-container case)
kubectl logs deploy/my-deployment -c my-container         # dump Pod logs for a Deployment (multi-container case)
```