Support for SSH internal IP

[D-Parker]

I've been using the github version of the library. My organization uses a VPC with subnetworks, but only allows SSH traffic between internal IP addresses. I run Rstudio on a Linux VM instance within the subnetwork. Connecting to the VM instances created by the library via SSH works for me after I manually reassign the IP with this command:

vm$networkInterfaces$accessConfigs[[1]]$natIP <- vm$networkInterfaces$networkIP

Would it be possible to add built-in support for internal IP as an option? (If there is not some other way of setting it up that I have missed)

Thanks in advance

[MarkEdmondson1234]

Thanks for the how-to on doing it, looks very doable :)

Subnetwork support in general looks like the next feature to work on, similar to #154