Creating a policy sample containing cloud_admin, project_admin and project_member roles

Reading Nova policy, the roles are quite complicated, we don't know which roles are appropriated for each user. For example, in nova policy just the admin role is described. Our proposal is to clarify for the cloud user how's the role organizations, for example, cloud_admin is the role for the admins, project_admin for the project admin and project_member a member with a role in a project but with no admin permissions
The ideia is create a policy.cloudsample.json, where was defined roles as a project_admin, cloud_admin and project_member and determine their permissions, making policy Nova closer to the business reality.