Add yaml-rust to the test suite

[FichteFoll]

Rust has a yaml implementation named "yaml-rust": https://github.com/chyh1990/yaml-rust

Its readme declares it's "still under heavy development", so I'm just letting you know it exists~

[perlpunk]

@FichteFoll thanks.
The implementation itself has to be added to the https://github.com/yaml/yaml-editor.
yaml-editor is the project which installs all frameworks into a docker container.

The yaml-test-matrix is running the different framework scripts from this docker container, eventually transforms their output to be comparable to the yaml-test-suite event format (or to json) and creates a html matrix from the comparison results. I thought about visualizing this on the matrix page,not exactly sure how yet =)

I created yaml/yaml-editor#14

[perlpunk]

yaml-rust is now included in yaml-runtimes https://github.com/yaml/yaml-runtimes and in the matrix: https://matrix.yaml.info/