uninstall_packaged_incremental shouldn't fail if there is nothing to delete
uninstall_packaged_incremental shouldn't fail if there is nothing to
delete

cdcarter/CumulusCI,Joble/CumulusCI,SalesforceFoundation/CumulusCI,SalesforceFoundation/CumulusCI,e02d96ec16/CumulusCI,e02d96ec16/CumulusCI