remove namespace property from wskprops

[rabbah]

The setting of a namespace in wskprops can lead to surprising failures when it does not match the auth key. This value used to be there when namespaces and keys were not 1-1 but that hasn't been the case for a long time.

This patch remove --namespace from property set/unset but preserves --namespace in property get.

Partially fixes #137. Will open a subsequent PR to re-purpose wsk namespace get.

[neerajmangal]

sorry @rabbah, for the late response. I tested the changes and all looks good.

[sciabarracom]

I built the cli and I tried with an existing configuration with a namespace:

Old:
wsk -i action list
error: Unable to obtain the list of actions for namespace 'neuronix_cloud': The supplied authentication is not authorized to access 'neuronix_cloud'. (code nVQD2dAZZbjgN4Z1fqsXkE7Q8aAFVFSi)
Run 'wsk --help' for usage.

New:
./wsk -i action list
actions

[sciabarracom]

works for me

[rabbah]

Thanks @neerajmangal @sciabarracom.

[devaughnsaxa]

@rabbah I think this doc needs update then
https://openwhisk.apache.org/documentation.html#wsk-cli

It still shows the --namespace flag