Mount aws-machine-controller binary only in development case

[csrwng]

Creates a separate cluster-operator-ansible image that supports the binary mount of aws-machine-controller. That way, if you want to use the normal non-hacky way of running aws-machine-controller, you can specify the original image when deploying cluster-operator:

./contrib/ansible/deploy-devel-playbook.yml -e ansible_image=cluster-operator-ansible:canary

The default will be to use the new :dev tag so that we get our code onto the target cluster.

It also includes the fix to copy the machine controller binary to all masters, enabling support for > 1 master.

[csrwng]

@dgoodwin ptal

[dgoodwin]

/lgtm