Vitrage: add missing machine-learning Docker image
Vitrage: add missing machine-learning Docker image

A new service was added to Vitrage, the machine learning service.
https://github.com/openstack/vitrage/blob/master/releasenotes/notes/machine_learning_service-da9700e6c6fa61b6.yaml#L2

Change-Id: I78dcb2b57d61483b8996a13b8964b79d7b799cae
Closes-Bug: #1714234

stackforge/kolla,nihilifer/kolla,nihilifer/kolla,stackforge/kolla,stackforge/kolla,rahulunair/kolla,openstack/kolla,rahulunair/kolla,openstack/kolla