955706 - updates to renable support for system groups

This pull request includes updates to re-enable support for system groups (along with the needed vcr cassettes). The following is a high-level summary:
    
1. provides support for the following actions:
    pkg install/update/remove
    pkg group install/update/remove
    errata install
    
2. supports importing gpg keys on client during install/update actions
    
3. update the task status and event history to support the new formatted responses

This PR by itself will have a few test failures until the corresponding changes are merged in to runcible and available.  Those changes are tracked https://github.com/Katello/runcible/pull/69.