libcnab: CNAB library for Rust

This is a highly experimental (and currently unfinished) implementation of CNAB Core 1.0. It is written in Rust.

Progress:

• implement bundle.json structs
• test deserialize
• write Canonical JSON
• read/write bundle.json from files and strings
• execute a bundle in Docker
• support custom actions

We're just learning Rust, so we welcome feedback and PRs.