In the current doc, the command examples are like
"os server create" but the acutal command should
be started with "openstack" instead of "os", it
is misleading to first time users.
Change-Id: Ic7686257725e1aa8e4e0d65a712eff1c079927a8
Commands are "ec2 credentials delete", "service delete", "endpoint delete".
Also update their unit tests and functional tests.
Partial-Bug: #1592906
Change-Id: I1a0b7160b803a523646d09d030e6f112c81c4c24
<service> argument of `endpoint create` command doesn't mean
`new endpoint service`, but an existent service that the new endpoint attached to.
Change-Id: I846fdb501bdea14499f42288186f375a3b2b5951