This changes the scope validation to occur after a token has already
been created.
Previous flow:
1. Validate authentication options.
2. Validate authorization options if the command requires a scope.
3. Create a token (using authentication + authorization options)
4. Run command.
This means that scope was being checked, even if a default scope was
applied in step 3 by Keystone.
New flow:
1. Validate authentication options.
2. Create token (using authentication + authorization options)
3 Validate authorization options if the command requires a scope and
the token is not scoped.
4. Run command.
Change-Id: Idae368a11249f425b14b891fc68b4176e2b3e981
Closes-Bug: 1592062