Add ability to map container name to pod name

[rcernich]

Some existing test suites use container names that can't be manifest in certain environments (e.g. upper case letters in k8s). Allowing users to manually specify the mapping between container name (arq) and container name (runtime) would alleviate this issue.

[rcernich]

Added support for a "cubeId" property on the container configuration. This should default to the container name if no cubeId is specified.

[jwendell]

I suggest you guys to put something like "Closes #NNN", or "Fixes #NNN" into the commit messages so that github automatically closes the issues when the PR is merged :)