Issue 99 - Fix typo in create_topology
    
    Description: We need to use the roles from the 'for' loop while creating
    agreements. If we don't, we will have failures while creating 'asymmetric'
    setups like two masters and one consumer.
    
    https://pagure.io/lib389/issue/99
    
    Reviewed by: amsharma, sramling (Thanks!)