Change the token verb to issue/revoke

Change the token verb to issue/revoke as documented in:

https://wiki.openstack.org/wiki/OpenStackClient/Commands#token
https://wiki.openstack.org/wiki/OpenStackClient/Commands#Actions

Change-Id: I44f77f98ad3269c4f2149301c204804dcb75ac81
Merge "Change the token verb to issue/revoke"