Create Packer templates from a sessionInfo

[nuest]

HashiCorp's Packer is a neat way to build many different containers or VMs from one configuration file.

See https://www.packer.io/intro/getting-started/build-image.html for how a template looks like

via https://twitter.com/KathrynElliott/status/974876673559719936?s=09)

• [ ] create a packer.io template from an R sessionInfo
• [ ] find out if there is really no rstats package yet wrapping Packer...