Return ContainerConfig exposedPorts if no HostConfig boundPorts found

[aslakknutsen]

In this scenario boundPort is set to -1.

fixes #208

I updated the 'ping' polling option to take the -1 boundPort into account. Not sure if there are other places we need to handle this as well?

[lordofthejars]

Maybe when you use @HostPort in ContainerObject

arquillian-cube/docker/docker/src/main/java/org/arquillian/cube/docker/impl/client/containerobject/CubeContainerObjectTestEnricher.java

Line 182 in e53596e

field.set(containerObjectInstance, bindingForExposedPort.getBindingPort());

where we can decide if we let user to receive a -1 or throw an exception.

[aslakknutsen]

Added this: https://github.com/arquillian/arquillian-cube/pull/210/files#diff-9c660a5a29c9fc18b6b22ba056254c8eL181