Rewrite list_aggregates() in framework_sfa.py now that get_aggregates() is no longer supported by SFA.  Replace by pulling the peers from the slice manager's GetVersion call.
Rewrite list_aggregates() in framework_sfa.py now that get_aggregates() is no longer supported by SFA.  Replace by pulling the peers from the slice manager's GetVersion call.

tcmitchell/geni-tools,ahelsing/geni-tools,tcmitchell/geni-tools,GENI-NSF/gram,plantigrade/geni-tools,ahelsing/geni-tools,plantigrade/geni-tools,GENI-NSF/gram,GENI-NSF/gram