Update srcd/ml-core container automatically

[zurk]

we have such updates for https://hub.docker.com/r/srcd/ml, but not for https://hub.docker.com/r/srcd/ml-core

We should add it.
@vmarkovtsev, as I understand only you in the team, have permissions for it.

[zurk]

If someone interested I have a workaround for now. I build and push container to my docker hub account: https://hub.docker.com/r/kslavnov/ml-core/tags/