Revert "add option to list all role members"

This reverts commit d15feb90f9f4085566d5cf647d21075d7e99dc0d.
Use rubygems version of the api gem by default.
Refactored spec and cli to better support speccing.
Running a command destroys argv. Clone it before handing out.
Spec for role:memberships.
role:memberships now correctly supports non-user roles.
Fixes BC#41569208-normal-bug
Use GLI_DEBUG instead of rolling our own (thanks Kevin!)
Spec and fix the case for parametrized role:memberships.
print messages on role creation, grant, and revoke
Merge pull request #3 from inscitiv/role-memberships-nonuser

role:memberships now works correctly for non-user users