Add actions to operate on role entity

[OpenStack Infra]

https://review.openstack.org/159820
commit 422414d231ddbfd5cf1f8b3b5af560a9f119acba
Author: Dmitry Shulyak <email address hidden>
Date: Fri Feb 27 14:36:16 2015 +0200

    Add actions to operate on role entity

    Commands to read/create/delete/update roles in fuel

    Save role data into file:

    fuel role --role compute --rel 1 --file compute.yaml

    Read and update role in fuel

    fuel role --rel 1 --update --file compute.yaml

    Delete role from fuel

    fuel role --rel 1 --role compute --delete

    Create role

    fuel role --rel 1 --create --file new_role.yaml

    DocImpact
    implements blueprint create-role-with-nailgun-api

    Change-Id: I2f948c03de5de4ff859df3e7d1bde9cb3c226030