Bridge Networking Support

[mattBrzezinski]

In order to work with bridge networking in ECS we need to use the ECS API more. The basics of how we could support bridged networking is:

1. Launch the worker tasks
2. Use the task IDs from the output of the launch and use describe-tasks to determine the host port used (when ephemeral is used)
3. Determine the address of the containers instance (container-id to instance-id to IP address)
4. Manager connects to workers using the information gathered

Additionally we probably want to be able to determine if a task is using "bridge" or "host" networking. We can easily determine which "networkMode" was used via describe-task-definition. Note, this may not be enough as the "networkMode" may be overridden. In that case we would have to check the task itself.