Object: refacor of x509keypair.py
Object: refacor of x509keypair.py

1. Fix error doc string of list().
2. Move get_by_bay_uuid to group with get_by_*

Change-Id: Ifa7724decf6ae7d35a09631a31449aeec9adeb5b

dimtruck/magnum,openstack/magnum,ArchiFleKs/magnum,ArchiFleKs/magnum,jay-lau/magnum,dimtruck/magnum,openstack/magnum