**IMPORTANT NOTICE** OpenWhisk is updating it's authentication model. Users must update to the new authentication model in which each namespace now has a unique authentication key associated with it. This key will change as you switch namespaces in Bluemix so you must rerun this command if you switch your Bluemix organization or space. If you had previously set your namespace you must unset it when using the new authentication model. If you had not previously set a namespace you do not need to with the new authentication model, the namespace will be identified from the auth key.
The following command uses the old authentication. Users who ran this command should update to the new authentication model shown above.
echo, passing it "hello" as an argument.